Deirdre said quietly, "I would too, if I were swimming."

"Sound," said Terry, "in water as in air, can be reflected and directed,

just as light can be. A megaphone turns out one's voice in a cone of

noise, like a reflector on a light. It should be possible to project it.

One can project a hollow cone of light. Why not a hollow cone of sound,

in water?"

Davis said with an unconvincingly ironic and skeptical air, "Indeed, why

not?"

"If such a thing were done," said Terry, "then when the cone of sound

was turned on, the fish inside it would be captured as if by a conical

net. They couldn't swim through the walls of sound. And then one can

imagine the cone made smaller; the walls drawn closer together. The fish

would be crowded together in what was increasingly like a vertical,

conical net, but with walls of unbearable noise instead of cord. It

would be as if the sea were electrified and the fish were shocked when

they tried to pass a given spot."

"Preposterous, of course," said Davis. But his tone was not at all

unbelieving.

"Then suppose something were sent up to the top of the cone, and it

projected some kind of a cover of sound on the top of the cone and

imprisoned the fish with a lid of sound they couldn't endure. And then

suppose that thing sank into the water again. The fish couldn't swim

through the walls of noise around them. They couldn't swim through the

lid of sound above them. They'd have to swim downward, just as if a hood

were closing on them from above."

"Very neat," said Davis. "But of course you don't believe anything of

the sort."

"I can't imagine what would produce that sound in that way and send up a

cork of sound to take the fish below. And I can't imagine why it would

be done. So I can't say I believe it."

Davis said slowly, "I think we begin to understand each other. We'll

stay as close to this place as we can until dawn, when we will find

nothing to show that anything out of the ordinary happened here."

"Still less," said Terry, "to hint at its meaning. I've been doing sums

in my head. That bright water was almost solid with fish. I'd say there

was at least a pound of fish to every cubic foot of sea."

"An underestimate," said Davis judicially.

"When the bright patch was a thousand yards across--and it was even

more--there'd have been four hundred tons of fish in the top three-foot

layer."

Davis seemed to start. But it was true. Terry added, "The water was

clear. We could see that the packing went on down a long way. Say fifty

yards at least."

"Y-yes," agreed Davis. "All of that."

"So in the top fifty yards, at one time, there were at least twenty

thousand tons of fish gathered together. Probably very much more. What

_La Rubia_ carried away couldn't be noticed. All those thousands of tons

of fish were pushed straight down. Tell me," said Terry, "what would be

the point in all those fish being dragged to the bottom? I can't ask who

or what did it, or even why. I'm asking, what results from it?"

Davis grunted.

"My mind stalls on who or what and why. And I'd rather not mention my

guesses. I.... No!"

He moved abruptly away.

The _Esperance_ remained under sail near the patch of sea that had

glittered earlier and now looked exactly like any other square mile of

ocean. The recorder verified the position by giving out, faintly, the

same unpleasant humming noise, either louder or fainter. A soft warm

wind blew across the waters. The land was somewhere below the horizon.

The reel of recorder-tape ran out. It was notable that there were very

few fish sounds to be heard, now. Very few. But the hum continued.

Toward morning it stopped abruptly. Then there was nothing out of the

ordinary to be observed anywhere.

The sun rose in magnificent colorings. The sky was clear of clouds.

Again the waves looked like living, leaping, joyous things. Gulls were

squawking.

Doug came up from belowdecks. He carried some photographic prints in his

hand. He'd developed and printed what the gun-cameras had photographed

when the mysterious object, or beast, leaped clear of the sea. There

were seven different pictures. Four showed flashbulb-lighted sections of

empty ocean. One showed a column of sea water rising at fantastic height

from the sea. Another one showed the edge of something at the very edge

of the film.

The seventh picture Terry recognized. It was what he'd seen when the

flashbulb of his gun-camera went off. The focus was not sharp. But it

was neither a whale nor a blackfish--not even a small one--nor was it a

shark. It was not a squid. It was not even a giant manta. The picture

was a blurry representation of something unreal made for an unimaginable

purpose, under abnormal conditions.

Deirdre looked at it over his shoulder. It could be a living creature.

It could be ... anything.

"You said you didn't like mysteries," commented Deirdre. "Are you sorry

you came?"

_Four_

The next morning the _Esperance_ headed southeast over a sunlit sea.

First, of course, the crew examined the sea's surface for miles around.

As expected, there was nothing remarkable to be observed. Davis did

point out that there were no fish jumping, which was an indication that

there were not as many fish as usual in this part of the ocean. But it

was hard to be sure. There is no normal number of times when fish will

be seen to jump. They usually jump to escape larger fish that want to

eat them. The number is pure chance. But there seemed to be almost no

jumps at all this morning.

It was not discussed at length, however. All the ship's company was

curiously reluctant to refer to the events of the previous night. In

broad daylight, a detached review was simply impractical. With gulls

squawking all about, with seas glinting in the sunshine, with decks to

be washed and breakfast to be eaten, and commonplace, routine

ship-keeping to be done, the adventure of the patch of shining sea

seemed highly improbable. Terry felt that it couldn't really have

happened. To discuss it seriously would be like a daylight ghost tale.

One was unable to believe it in daylight. It was better ignored.

Terry, though, did get out his tools to make a minor modification in the

underwater microphone. It had been designed to be directional, so that

the sound of surf or fish could be located by turning the mike, but he

hadn't been able to point it vertically downward, and last night that

had been the key direction--right under the yacht's keel. So now he

improvised gimbals for the microphone, and a mounting for it similar to

that of a compass, so it could tilt in any desired direction, as well as

turn.

Which, of course, was a tacit admission that something peculiar had

happened. Presently, Deirdre came and watched him.

"What's that for?" she asked, when he fitted the gimbals in place.

He told her. She said hesitantly, "Yesterday, when I asked you not to

try the paddle until we got to shallow water, you got angry and said

you'd ask to be put ashore. We're headed for Barca now. Someone there is

building something for my father, the same thing I had asked you to

build--a fish-driving instrument. If you still want to go, you can get a

bus from there to Manila. But I hope you have changed your mind."

"I have," said Terry dourly. "I told your father so. I was irritated

because I couldn't get any answers to the questions I asked. Now I've

got some questions your father wants answers to. And I'm going to try to

find them out."

Deirdre sighed, perhaps in relief.

"I put some pictures and a clipping in a book on the cabin table," she

said. "Did you see them?"

He nodded.

"What did you think?"

"That you put them for me to see," he said.

"It was to make you realize that we can't answer every question, which

you know now."

"I still think you could answer a few more than you have," he observed.

"But let it go. Is the Barca harbor shallow?"

"Ten, fifteen feet at low tide," she informed him. "We're having a sort

of dredge made there. Something to go down into the sea, take pictures,

get samples of the bottom, and then come up again. There's an

oceanographic ship due in Manila shortly, by the way. It will have a

bathyscaphe on board. Maybe that will help find out some answers." Then

she said uncomfortably, "I have a feeling the bathyscaphe isn't ...

safe."

He glanced up.

"_Ellos?_" He grinned as she looked sharply at him. Then he said, "This

dredge: isn't it pretty ambitious for a boat this size to try to dredge

some thousands of fathoms down?"

"It's a free dredge," she said. "It will sink by itself and come up by

itself. There's no cable. What are you doing now?"

He'd put away the submarine microphone he'd just altered and was now

taking out the still untested underwater horn.

"I'm going to try to make this directional, too," he said. "In fact, I'm

going to try to make it project sound in a beam shaped like a fan. A

hollow cone may come later."

She was silent. The _Esperance_ sailed on.

"Ever talk to the skipper of _La Rubia_?" he asked presently.

She shook her head.

"You should. He's a stupendous, self-confident liar," said Terry. "He

lies automatically. Gratuitously. A completely amiable man, but he can't

tell the truth without stopping to think."

"We found that out," said Deirdre. "I didn't. Someone else."

"Is this another censored subject, or can I ask what happened?"

"I'd better see about lunch," said Deirdre quickly.

She got up and left. Terry shrugged. The day before yesterday, or even

yesterday, he'd have been indignant. But then he'd known these people

had secrets in which he had no share. Today he was beginning to share

those secrets, and he had fabulously nonsensical material on which to

work on his own. He had strange ideas about the event of last night. He

did not quite believe them, but he thought he had devised some ways to

see how much of truth they contained, if any. Deirdre could keep her

secrets, so long as he did not have to disclose his own wildly

imaginative ideas.

The routine of the yacht went on. It was in a way a very casual routine.

Davis gave orders when the need arose, but there was no formal

discipline; there was co-operation. Terry heard one of the crew-cuts ask

Deirdre a question using her first name. It would have been highly

improbable in a paid crew, but it was reasonable enough in a volunteer

expedition. He heard Deirdre say, "Why don't you ask him?"

The crew-cut, Tony, came to the part of the deck where Terry worked.

"We got into an argument," he said without preface. "We were talking

about that ... 'whale' last night."

Terry nodded. The use of the term "whale" was a deliberate pretense that

the previous night's events were natural and normal.

"How fast do you think it was traveling when it broached?" asked Tony.

"I know a whale can jump clear of the water. I've seen it in the movies.

But that one jumped awfully high!"

"I hadn't tried to estimate it," said Terry.

"You've got a tape of the noise," said Tony. "Could you time the

interval between the sound when it left the water, and the splash when

it fell back?"

"Mmm. Yes," said Terry. He looked up. "Of course."

"It would be interesting to do it," said Tony, semicasually. Then he

added hastily, "I've read somewhere that whales have been clocked at

pretty high speeds. If we can find out how long its leap lasted, we

could know how fast it was going."

Terry considered for a moment, and then got out the recorder. He played

the tape for a moment, and skipped forward to later parts of the record

until he came to the place where the unpleasant humming sound was loud,

and finally reached the beginning of the rushing noise. That, in turn,

had preceded the leap of the object photographed by the gun-cameras.

Terry glanced at his watch when the rushing started. He timed the period

of ascent of the noise, while it grew louder and louder and became a

booming sound, which was at its loudest the instant before it ceased. At

that moment the mysterious object had leaped out of the sea. The splash

of its re-entry came long seconds later.

Tony timed the leap. When the splash came he made his calculations

absorbedly, while Terry switched off the recorder.

"It would take the same amount of time going up as it does coming down,"

said Tony, scribbling numbers. "Since we know how fast things fall, when

we know how long they fall we can tell how fast they were traveling when

they landed, and therefore when they leaped."

He multiplied and divided.

"Sixty miles an hour, roughly," he pronounced. "The whale was going

sixty miles an hour straight up when it left the water! What can swim

that fast?"

"That's your question," said Terry. "Here's one of mine. We heard it

coming for five minutes ten seconds. How deep is the water where we

were?"

"About forty-five hundred fathoms."

"If we assume that it came from the bottom, it must have been traveling

at least sixty miles an hour when it broke surface," said Terry.

"But can a whale swim sixty miles an hour?"

"No," said Terry.

Tony hesitated, opened his mouth, closed it, and went away.

Terry returned to the changing of the submarine horn. Sound has its own

tricks underwater. If you know something about them you can produce some

remarkable results. A deliberately made underwater signal can be heard

through an unbelievable number of thousands of miles of seawater. But,

except through a yet untested fish-driving paddle, Terry had never heard

of fish being herded by sound. Still, fish can be stunned or killed by

concussions. They have been known to be made unconscious by the noise

of a very near submarine bell. It wasn't unreasonable that a specific

loud noise could make a barrier no fish would try to cross. But there

were still some parts of last night's events that did not fit into any

rational explanation.

Davis came over to Terry.

"I think," he said, "that we may have missed a lot of information by not

having submarine ears before. There may have been all sorts of noises we

could have heard."

"Possibly," agreed Terry.

"We're more or less in the position of savages faced with phenomena they

don't understand," said Davis vexedly. "The simple problems of savages

range from what produces thunder to what makes people die of disease.

Savages come up with ideas of gods or devils doing such things for

reasons of their own. We can't accept ideas of that sort, of course!"

"No," agreed Terry, "we can't."

"But what happened last night," said Davis, "is almost as mysterious to

us as thunder to a savage. A savage would blame it on devils or

whatnot."

"Or on _ellos_," said Terry.

"He'd imagine a personality behind it, yes," said Davis. "He does things

because he wants to, so he thinks all natural phenomena occur because

somebody wants them to. He has no idea of natural law, so he tries to

imagine what kind of person--what kind of god or devil--does the things

he notices. It's a natural way to think."

"Very likely," admitted Terry. "But the point?"

"Is that we mustn't fall into a savage's way of thinking about last

night's affair."

Terry said, "I couldn't agree with you more. But just what are you

driving at?"

"There's a dredge being made for me in Barca. I'm afraid you may suspect

that I'm trying to--stir up something with it. To poke something we

_know_ is somewhere but can't identify. I didn't want you to try the

fish-paddle in deep water, that's true. But...."

"You're explaining," said Terry, "that you didn't want me to whack a

fish-driving paddle overside in deep water."

Davis hesitated, and then nodded.

"The phenomena you're interested in are under water?"

"Yes," said Davis. "They are in the Luzon Deep area."

"Then, to be co-operative, I'll test this contrivance in ten to fifteen

feet of water in the Barca harbor. And I will not get temperamental

about your suggestions that I should not mess up your deep-water

inquiries."

"Thanks," said Davis.

He went forward to meet Nick, just coming abovedecks with a slip of

paper in his hand. It occurred to Terry, suddenly, that somebody went

below down the forecastle hatch just about every hour on the hour. They

must be in short-wave communication with Manila. It had been mentioned

last night--a loran fix on the _Esperance's_ position. There were

apparently frequent reports to somebody somewhere.

The afternoon went by. A tree-lined shore appeared to the eastward just

when the gaudy colorings of a beautiful sunset filled all the western

sky. The _Esperance_ changed course and followed the coast line, some

miles out. Night fell. The yacht sailed with a fine smooth motion over

the ocean swells.

After dinner Davis was below, fiddling with the knobs to pick up

short-wave music from San Francisco, and the muted sound of an argument

came occasionally from the forecastle where the four crew-cuts resided.

Terry and Deirdre went on deck.

"My father," said Deirdre, "says you understand each other better, now.

He doesn't think you're going to feel offended with us, and he's really

pleased. He says your mind doesn't work like his, but you come to more

or less the same conclusions, which makes it likely the conclusions are

right."

Terry grimaced.

"My conclusion," he observed, "is that I haven't enough facts yet to

come to any conclusion."

"Of course!" said Deirdre. "Just like my father!"

They sat in silence. It was not exactly a tranquil stillness. It was

pleasant enough to be here on the slanting deck of a beautiful yacht,

driving competently through dark seas under a canopy of stars. But now

Terry realized he was constantly aware of Deirdre. He liked her. But

he'd liked other people, male and female, without being continually

conscious of their existence. Girls are usually more conscious of such

things than men. At least ninety-nine per cent of the time, a man does

not modify his behavior because of the age, sex, and marital status of

the people he comes in contact with. It isn't relevant to most of what

he says and does. But a girl frequently modifies her actions in just

such circumstances. Deirdre was well aware of the slightly uneasy,

extremely interested state of Terry's mind. There was silence for a long

time. Then a shooting star went across the sky. It went out.

"Would you like to hear something really wild?" asked Deirdre, ruefully.

"That shooting star, just then. It used to be true that more

meteorites--shooting stars--had fallen and been recovered in Kansas than

any other place in the world. But it would be ridiculous to think they

aimed for Kansas, wouldn't it?"

Terry nodded, not following at all.

"At Thrawn Island," said Deirdre, "since the satellite-tracking station

has been built, space-radars have picked up more bolides--big

meteors--coming in to fall in the Luzon Deep than ever in Kansas or

anywhere else. I think my father frets over that, simply because he's so

concerned about the Luzon Deep."

Terry heard himself saying irrelevantly, "I'd like to ask you a few

strictly personal questions, Deirdre. What's your favorite food? What

music do you like? Where would you like best to live? When...."

Deirdre turned her head to smile at him.

"I've been wondering," she said, "if you thought of me only as a fellow

researcher or whether you'd noticed that I'm a person, too. Hmmmmm.

There's a restaurant in Manila where they still cut their steaks along

the muscle instead of across it, but where they make some unheard-of

dishes. That place has some of my favorite foods. And...."

"Next time we're in Manila we'll try it," said Terry. "Now, I know a

place...."

The _Esperance_ went on. Presently, the moon rose and moonlight glinted

on the waves while the stars looked cynically down on the small yacht

upon the sea. And two people talked comfortably and absorbedly about

things nobody else would have thought very interesting.

When Terry turned in for the night he realized pleasantly that he was

very glad he'd let himself be persuaded to join the _Esperance's_

company.

Dawn came. Terry was already on deck when the _Esperance_ threaded her

way into a small harbor. There were palm trees along the shore, and

there was a Philippine town with edifices ranging from burnt brick to

stucco to mere nipa huts on its outskirts. Two-man fishing boats were

making their way out from the shore on which they'd been beached. From

somewhere came the staccato, back-firing noise of an old

automobile-engine being warmed up for the day's work. It would

undoubtedly be the bus for Manila. But it was not thinkable that Terry

should take it, now.

The yacht dropped anchor and lay indolently at rest while her crew

breakfasted and the morning deck routine was being performed. Then

Deirdre appeared in shore-going clothes of extreme femininity. Davis too

was dressed otherwise than as usual.

"We're going ashore to the shipyard," he told Terry. "If you'd like to

come--"

"I've something to do here," said Terry.

Two of the crew-cuts got a boat overside and headed it for the shore.

Terry got out the recorder and the submarine ear and horn. He set up his

apparatus for a test. Tony came from belowdecks and watched. Then he

came closer.

"If I can help," he said tentatively.

"You can," Terry told him. "But let's listen to what the fish are

saying, first."

He dropped over the submarine ear and started the recorder to play what

it picked up, but without recording it. Sounds from underwater came out

of the speakers. The slappings of tiny harbor-waves against the yacht's

planking; the chunking, rhythmic sound of oars from a fishing boat which

was rowing after the half-dozen that had gone out earlier; grunting

sounds. Those were fish.

Terry listened critically, and Tony with interest. Then Terry brought

out the fish-driving paddle. He turned on the tape, now, to have a

record of the sound the paddle made.

"Whack this on the water," he suggested, "and we'll hear how it sounds."

Tony went down the ladder and gave the water surface a few resounding

whacks. There were tiny, violent swirlings. For thirty or forty feet

from the _Esperance's_ side there were isolated, minute turmoils in the

water. Three or four fish actually leaped clear of the surface.

"Not bad!" said Tony. "Shall I whack some more?"

Terry reeled back a few feet of the tape which contained the whacking

sounds. He re-played them, listening critically as before. Tony had

returned to the deck. The whackings, as heard underwater, were not

merely impacts. There was a resonance to them. Almost a hum. Rather

grimly, Terry substituted this tape-reel with the recording he'd made

the night before. He started the instrument and found the exact spot

where the object from the depths had fallen back into the sea. He

stopped the recorder right there. He hauled up the submarine ear and

plugged in the horn to the audio-amplifier, as yet untested, which

should multiply the volume of sound from the tape. Then he put the horn

overside.

He switched on the recorder again. The tape-reel began to spin. The

sound went out underwater from the horn. Underwater it was much louder

than when it had been received by the _Esperance's_ microphone. Here it

was confined by the surface above and the harbor-bottom beneath. It must

have been the equivalent of a loud shout in a closed room--only worse.

The fish in the harbor of Barca went mad. All the harbor-surface turned

to spray. Creatures of all sizes leaped crazily above the surface, their

fins flapping, only to leap again, more frantically still, when they

fell back. A totally unsuspected school of very small flying fish

flashed upward in such frenzied haste that some tried to climb too

steeply and fell back and instantly flung themselves into the air again.

Terry turned off the playing recorder. The disorder at the top of the

water ceased immediately. But he heard shrill outcries. Children had

been wading at the edge of the shore. They stampeded for solid ground,

shrieking. Where their feet and legs had been underwater they felt as if

a million pins and needles had pricked them.

Something flapped heavily on the _Esperance's_ deck. Tony went to see.

It was a three-pound fish which had leaped clear of the water and over

the yacht's rail to the deck.

Tony threw it back into the water.

"I guess there's not much doubt," he said painfully.

"Of what?" demanded Terry.

"Of what ... I had guessed," said Tony.

"And what did you guess?"

Tony hesitated.

"I guess," he said unhappily, "that I'd better not say."

He watched with a startled, uneasy expression on his face as Tony put

the apparatus away.

Time passed. Davis and Deirdre had been ashore over an hour. Then Terry

saw the small boat leave the shore and approach. It came deftly

alongside, the two passengers climbed up to the deck, and all four

crew-cuts hauled the boat back inboard and lashed it fast.

"Our dredge isn't ready yet," said Davis. "It looks good, but there'll

be a delay of a few days."

Deirdre examined Terry's expression.

"Something's happened. What?"

Terry told her. Davis listened. Tony added what he'd seen, including the

fish that had leaped high enough out of the water to land on the

_Esperance's_ deck.

"After the fact," said Davis, "I can see how it could happen. But...."

He hesitated for a long time and then said, "This is another case where

I've been making guesses and hoping I was wrong. And like the others,

proof that my early guess was wrong makes another guess necessary. And I

dislike the later guess much more than the first."

He moved restlessly.

"I'm glad you only tried it once, here," he said unhappily. "We're due

up at Thrawn Island anyhow. You can work this trick out in the lagoon up

there. If there's no reaction to the dredge when we try it, we can try

this. But it might be a very violent poke at something we don't quite

believe in. I'd rather try a gentle poke first."

He turned away. In minutes Nick was belowdecks starting the yacht's

engine, two others of the crew-cuts were hauling up the anchor, and the

fourth was at the wheel. Without haste, but with celerity, the

_Esperance_ headed for the harbor-mouth and the open sea.

They had their midday meal heading north by west. Late in the afternoon

Deirdre found occasion to talk to Terry about Thrawn Island.

"It's the China Sea tracking station for satellites," she told him.

"Some of the staff are friends of my father's. It's right on the edge of

the Luzon Deep, and the island's actually an underwater mountain that

just barely protrudes above the surface. There are some hills, a coral

reef and a lagoon. It's also terrifically steep, and you can use the

fish-driving device as much as you please without startling any Filipino

fishermen."

"You've been there before," said Terry.

"Oh, yes! I told you a fish wearing a plastic object was caught in the

lagoon there. That was when the station was being built. The men at the

tracking station fish in the lagoon for fun, and now they're naturally

watching out for more ... oddities."

The _Esperance_ sailed on. The crew-cuts went about their various chores

and talked endlessly, among themselves and with Deirdre, when she joined

in. Terry felt useless. He trailed the submarine ear overboard and set

the recorder to work as an amplifier only. At low volume it played the

sounds of things below. He kept half an ear cocked toward it for the

mooing sound he'd picked up at the place where the ocean glittered. He

heard it again now, and again found it difficult to imagine any cause

for it. The sounds uttered by noisemaking fish are usually produced in

their swim-bladders. The purpose of fish cries is as obscure as the

reason for some insect stridulations, or the song of many birds. But a

long-continued fish noise would involve a swim-bladder of large size. At

great depths, if a considerable cavity were filled with gas, under

pressures running into tons to the square inch.... Terry could not

quite believe it.

He did not hear the mooing sound any more, as the yacht went on its way.

Other underwater sounds became commonplace, and he tended not to hear

them. From the deck around him, though, he heard arguments about wave

mechanics, prospects in the World Series, the virtues of Dixieland jazz,

ichthyology, Copeland's contribution to modern music, the possibility of

life on other planets, and kindred topics. The crew-cuts were taking

their summer vacations as able seamen on board the _Esperance_, but they

had as many and as voluble opinions as any other undergraduates. They

aired them on each other.

The afternoon passed. Night fell, and dinner was a session of learned

discussion of different subjects, always vehemently argued. Later Terry

took the yacht's wheel, Deirdre sat comfortably nearby, and they

discussed matters suitable to their more mature status. They were much

less intellectual than the crew-cuts. In a few days they developed an

interest in each other, but each of them believed this was just a very

pleasant friendship.

Eventually, the moon rose. It was close to midnight when Nick bobbed

belowdecks and came up with a report that they'd been picked up by the

Thrawn Island radar and were proceeding exactly on course. Half an hour

later a tiny light appeared at the edge of the sea. The _Esperance_

headed for it, and presently there were breakers to port and starboard,

the engine rumbled, down below, and the yacht lifted and fell more

violently than ordinary. Then once more she was in glassy-smooth water;

the air was very heavy with the smell of green vegetation. Certain

rectangles of light became visible. They were the windows of the Thrawn

Island satellite-tracking installation.

The _Esperance's_ sails were lowered and she moved toward the lights on

engine power only. There was no movement ashore, though Nick had talked

with the island on short-wave.

After a little while the searchlight was put in operation and began to

reach out like a pencil of brilliant white light. It darted here and

there and found a wharf reaching out from the shore to deep water. The

_Esperance_ floated toward it, her engine barely turning over. There was

still no sign of activity, except for the lighted windows.

The engine stopped, then reversed, and the yacht drifted gently until it

contacted the wharfs snubber-pilings. Jug and Tony jumped ashore with

lines to fasten the yacht. Still no sign of life.

"Queer," said Davis, staring ashore. "They knew we were coming!"

A moving light suddenly appeared in the sky. A fireball, which is an

unusually lurid type of shooting star. It came over the tree-tops and

crossed the zenith, leaving a trail of light behind it. It went on and

on, seemingly slowing down, which meant that it was descending from a

very high altitude. Its brilliance became more and more intense, then it

dimmed. At this point the fireball seemed to plunge downward. Then its

flame went out and only a faint, dull-red speck in motion could be seen.

It plunged down beyond the trees on the far side of the lagoon. Or so it

seemed. Actually, it might have plunged into the sea, miles away. Then

there was a faint noise which was something between a rumble and a hiss.

The sound went back across the sky along the path the fireball had

followed. It died away.

There was silence. Shooting stars as bright as this one are rare. Most

meteors are very small, but they are visible because of the attrition

produced by their falling bodies in the atmosphere that sets them on

fire. They usually appear at around a seventy-mile height, but

frequently they are vaporized before they have descended more than

thirty miles. Sometimes they explode in mid-air and strew the earth with

fragments. Sometimes they strike ground, leaving monstrous craters where

they have fallen. Most meteors fall in the sea. But a meteor has to be

at least down to twenty miles from sea level before its sound can be

heard.

Someone came out of a building and moved toward the wharf, an electric

lantern bobbing in his hand. Halfway out to the yacht he called,

"Davis?"

"Yes," said Davis. "What's happened?"

"Nothing," said the man ashore. "We were watching for that bolide. It

was picked up by space radar a couple of hours ago, but then we figured

it to land farther on than it did."

It was an educated voice, a scholarly voice.

"Big?" asked Davis as the light drew nearer.

"We've seen them bigger, but not much." The man with the lantern reached

the end of the wharf. "Glad to see you. We've got some fish for you, by

the way. We caught them in the lagoon. They're waiting for you in the

deep-freeze. There's a _Macrourus violaceus_, if we read the books

right, and a _Gonostoma polypus_. They match the pictures, anyhow. What

do you make of that?"

"You haven't got them!" said Davis incredulously. "You can't have them!

I'm no fish specialist, but those are abyssal fish! They can only be

caught at a depth of two or more miles!"

"We caught 'em," said the man cheerfully, "on a hook and line, in the

lagoon, at night. Come ashore! Everybody'll be glad to see you."

Davis protested, "I won't believe you've got that kind of fish until I

see them!"

The man with the lantern stepped down to the yacht's deck.

"All you've got to do is look in the mess hall deep-freeze. The cook's

complaining that they take up space. Nobody wants to find out if they're

good to eat. Most unwholesome-looking creatures! And how are you, young

lady?" he asked Deirdre. "We've missed you. Tony, Nick, Jug...."

Deirdre introduced Terry.

"Ha!" said the man. "They got you enlisted, eh? They were talking about

it a month ago. You've solved the problem by now, I daresay. Including

how these very queer fish happen to be in our lagoon instead of miles

down in the Luzon Deep. When you find time, tell me!"

"I'll try," said Terry reservedly.

The man went down into the after-cabin and Davis followed him. Deirdre

said amusedly:

"Dr. Morton's a dear! Don't take him seriously, Terry! He loves to

tease. He'll hound you to tell him how deep-sea fish got up here and

into a shallow lagoon. Please don't mind!"

"I won't," said Terry. "I'll tell him tomorrow, I think. I believe now I

know how it happened, but I want to check it first."

_Five_

When Terry awoke, next morning, the reflections of sunlight on water

came in through the porthole of his cabin. He watched the shimmering

contortions of the light spots on the wall. His thoughts went instantly

back to the subject they'd dwelt on before he went to sleep. The man

with the spectacles--Dr. Morton, but his doctorate was in astronomy

instead of medicine--had said that Deirdre and his father had discussed

enlisting him in the _Esperance's_ company a month ago. Deirdre'd come

into the shop of Jimenez y Cía. only four days before. Some of the delay

could have been caused by time spent in simple sailing from one place to

another, mostly on wholly futile errands. They'd gotten a fish-driving

paddle at Alua. That'd take some days of sailing each way. Apparently,

they'd been fumbling at some vague idea of trying to find out what would

produce the facts they'd noted. 'Very queer fish,' Davis had said of

some of the catches _La Rubia_ had made. The abyssal fish mentioned last

night would be very queer fish to catch in a lagoon. Yes....

He lay still, surveying other aspects of the situation. Davis had called

on an aircraft carrier for electronic items, and the _Esperance_ was in

constant touch with somebody by short-wave radio. It might be the same

carrier. The Manila police department was on very cordial terms with

Davis, and the staff of a satellite-tracking installation saved odd

specimens of fish for him.

The _Esperance's_ enterprise was plainly not a brand-new adventure. It

had been carried on for some time. They had had technical aid of the

very highest caliber, but they hadn't gotten anywhere yet. It did

appear that Terry had added a minor specialty to the arsenal of

investigative techniques. Without the data gathered on recorder-tape,

their idea of the events of two nights before would be very different.

The sea would have seemed very bright, then the glowing area would have

been noted to have grown smaller, and something resembling a whale would

have been seen leaping high above the water. Then the brightness would

have faded out. It would have been mysterious enough, but an entire

aspect of the phenomenon would have gone unnoticed. There was still no

answer to any of the far-reaching questions Terry had asked himself, but

most of them had never been asked before. Sea noises had proved to be

closely connected to whatever had to be found out. What was known about

them was due to his findings. He'd established a new frame of reference.

And he'd discovered the solution of a minor problem before the problem

was even stated. He had only to prove it. Then, of course, there would

be other problems arising from it.

He got up, put on swimming trunks, and duck trousers over them. He

slipped into a sweat shirt and went upon deck. Deirdre hailed him.

"Good morning! Everybody's over at the tracking station, arguing about

the bolide that went over last night. According to the radar, it plunged

into the sea, miles and miles away."

"What should it have done?" asked Terry. "I'm not familiar with

meteorites. Are they planning to dive for it?"

"Hardly!" Deirdre laughed. "It landed in the Luzon Deep." She waved a

hand in an inclusive gesture. "This island's on the brink of it. A

bathyscaphe might go down there--in fact, I think it's scheduled; you

know, the one I said was coming to Manila on the oceanographic ship? A

bathyscaphe can go that deep, but it's not likely to hunt for

meteorites."

"Ah," said Terry judicially. "Then what difference does it make where it

hit?"

"It didn't fall the way it should have," said Deirdre. "It was spotted

by space radar away out, and they tried to compute its path, but they

figured it wrong. Now they're trying to make it come out right by

allowing for the effect of the earth's magnetic field on a metal

meteorite. They're arguing and waving equations at each other."

"Let them," said Terry. "I have trouble enough with fish. Do you think I

could borrow a boat?"

"We've always been able to," said Deirdre. Then she added, "I've kept

your breakfast hot. While you eat it I'll get a boat."

She went below, and instants later was up again.

"I have a feeling," she said, "that something interesting is going to

happen. I'll be back."

She swung lightly to the wharf and headed for land. Terry went below, to

find his breakfast laid out on the cabin table. He settled down to it,

but first pulled a book from the shelves. It was a volume on

oceanography, and its pages showed that it had often been referred to.

He found the Luzon Deep described. Its area was relatively small, a mere

ninety-mile-long chasm in the sea-bed. But it was second only to the

Mindanao Deep in its soundings, and a close second at that. Its maximum

depth was measured at twenty-seven thousand feet. Over five miles. There

was a mention of Thrawn Island as being on the very edge of the Deep.

According to the book, the island was the peak of one of the most

precipitous and tallest submarine mountains in the world. Three miles

from where Thrawn Island lay, there were soundings of twenty-eight

thousand feet and upward. This depth extended as a trench....

The staccato roaring of an outboard motor sounded some distance away. It

bellowed toward the yacht, swung about, and cut off. Terry gulped down

his coffee and went abovedecks, just as Deirdre was fastening the small

craft alongside the yacht.

"Taxi?" she asked amiably. "I got the boat. Where to?"

Terry swung down and took the steering grip. He headed the boat away.

There was a box for bait, a few fishing lines, and even two highly

professional fish-spears on board. Fishing was not necessarily a

sedentary pastime here.

"We try the lagoon entrance," he said. "I've an idea. I noticed

something last night, when we came in."

"Do you want to brief me?"

"I'd rather not," he admitted.

Deirdre shrugged without resentment. The little craft went sturdily

toward the passageway to the open sea. She formed an arrowhead of waves

as she moved. She neared the points of land at the ends of the coral

formation enclosing the lagoon. Thrawn Island was not an atoll. But the

beaches were made of snow-white coral sand. Outside there was clear

water for a space and then a reef on which the seas broke.

Terry headed the boat toward the open sea. Almost immediately after,

there was nothing but the reef and the sea between the boat and the

horizon. He slowed the boat almost to a stop, well within the reef's

tumult. She swayed and rolled on the surging water.

"Stay here," he commanded. "I want to swim out and back."

He pulled the sweat shirt over his head. He jumped overboard, leaving

Deirdre in charge of the boat.

The world looked strange to him when waves rolled by higher than his

head. A few times the sky narrowed to the space between wave-crests.

Other times he was lifted upon a wave-peak, and the sky was illimitably

high and large, and the breaking seas on the nearby reef merely roared

and grumbled to themselves.

He swam out, away from the land. Suddenly his body began to tingle. He

stopped and paddled, analyzing the sensation. One side of his body felt

as if the most minute of electric currents entered his skin. It was not

an unpleasant sensation. Deirdre, in the small boat, was fifty yards

behind, watching him. As he swam on, the tingling grew stronger. He

dived. The tingling did not vary with depth. He came up, and he was

farther out than he'd realized.

He suddenly knew that he'd been incautious. There are currents which

flow in and out of lagoons. A barrier of reef affects them, too. Terry

found himself swimming in an outward-bound current, which pushed him out

and away from the island.

Within seconds the sensation in his body changed from a mere tingling

to torment. For a moment it was just very much stronger and slightly

painful, but a moment later it felt as if he swam among flames. It was

unbearable. His muscles were not contracted, as if by an electric shock,

but he couldn't control their reflexes. He found himself splashing

crazily, trying to fight his way out of the anguish which engulfed him.

He went under. His body had taken complete control over his mind, and he

found himself swimming frantically, underwater. He couldn't reach the

surface. His body tried to escape the intolerable agony in which it was

immersed but couldn't.

He heard a roaring sound, but it meant nothing. The roaring grew louder.

Finally, he did break surface for a few seconds, and he gasped horribly,

but then he went under. The roaring grew thunderous, and he broke

surface again....

Something seized his flailing arm and pulled him up. The arm ceased to

experience the horrible sensation of being in boiling oil. His hand

recognized a gunwale. He swarmed up the solid object with hands helping

him, and found himself in the boat, gasping and shivering, and cringing

at the bare memory of the suffering he'd undergone.

Deirdre stared at him, frightened. She swung the boat's bow shoreward.

The outboard motor roared, and the boat raced past the gap in the reef

and rushed toward the lagoon opening.

"Are you all right? What happened? You were swimming and suddenly...."

He swallowed. His hands quivered. He shook his head and then said

unsteadily, "I meant to ... check the reason those queer fish stay in

the lagoon. I thought that if they belonged in the depths and were

somehow carried out of them, they would try to get back. I found out!"

He felt an unreasonable relief when the lagoon entrance was behind the

boat. The glassy water was reassuring. The _Esperance_ looked like

safety itself.

"I think I know how they got here, now," he added. "We underestimated

what we're trying to understand. I'll be all right in a minute."

It was less than a minute before he shook himself and managed to grin

wryly at Deirdre.

"Was there a hum in the water?" asked Deirdre, still staring at him. "I

thought I heard it on the bottom of the boat. Was that the trouble?"

"Yes. I wouldn't call it a hum," Terry admitted. "Not any longer. Now I

know what a slow fire feels like."

"You frightened me," said Deirdre, "the way you splashed...."

"I heard the humming sound," said Terry, "last night when the yacht came

up to the island. We were perhaps a half-mile off-shore. It was very

faint, but I had the amplifier turned down low. The hum was at its

loudest just before we passed the reef, but nobody else noticed. When

Dr. Morton said there were abyssal fish in the lagoon, I knew why they'd

be there. I made a guess at what might drive them there. I went to find

out if I was right. I found out!"

"The hum?" asked Deirdre again. When he nodded, she said: "What are you

going to do now? What do you think makes the hum?"

"I'm trying hard not to guess what makes the hum," Terry told her.

"Insufficient data. I need more. I think I'll ask what other odd

phenomena have turned up in this neighborhood. Foam-patches on the sea?

I can't imagine a connection, but still...."

He swung the little boat alongside the docked _Esperance_ and held out

his hand to help Deirdre to the dock. His hand was wholly steady again.

She accepted the help.

"We'll go to the tracking station?"

"Yes. Everybody seems to be there," said Terry.

They heard a babble of voices coming from the satellite-tracking

station. As they approached the buildings, Terry looked around. Off at

one side there was the very peculiar aerial system by which tiny

artificial moons circling the earth could be detected by their own

signals. Minute spheres and cylinders and spiky objects and

foolish-looking paddle-wheels, whirling in their man-appointed rounds,

sent down signals with powers of mere fractions of a watt. This system

of aerials picked up those miniature broadcasts and extracted

remarkable amounts of information from them. It was possible to

determine the satellites' distance more accurately, by a comparison of

phase-changes in their signals, than if steel tape measures were

stretched up to make physical contact with them. The accuracy was of the

order of inches at hundreds of miles. Floating where the stars were

bright and unwinking lights against blackness and the sun was a disk

with writhing arms of fire, the small objects sent back information that

men had never possessed before and did not wholly know what to do with

now that they did. And there were other objects in the heavens, too.

There were satellites which no longer signaled back to earth. Some had

their equipment worn out. Some objects were satellites which had failed

to function from the beginning. Some were mysteries.

The bolide of the night before was a mystery. As Terry and Deirdre

entered the wide verandah of the recreation building for the station's

personnel, they heard Dr. Morton protesting, "But that's out of the

question! I agree that we never know any more about what the Russians

throw out to space than what we find out for ourselves. That's true! But

this wasn't a terrestrial object! If it was a satellite that wasn't

launched right, it had to be sent up from Russian territory. It wasn't.

That's positive! If we assume it was a satellite that had already made

several orbital turns, we must admit it would be an impossible shift in

apogee for it to come down at the angle it did!"

Deirdre and Terry sat down as someone else said hotly, "Our observations

were wrong. They had to be! The earth's magnetic field couldn't affect

the speed of an object _outside_ the atmosphere! Our observations say it

slowed down. It couldn't!"

Davis lifted a hand in greeting. The argument stopped for a moment.

Deirdre was known, but Terry had to be introduced. He was sitting beside

a bald young man who explained in a low tone, as the argument resumed.

"They're having fun. They argued for days when our radar picked up an

empty second stage in orbit. They're still ready to dispute for hours

about a supposed retrograde satellite that was spotted last year, was

watched for four turns, and then disappeared. Beer?"

"Too early," said Terry. "Thanks just the same."

Davis said earnestly, at the other side of the room, "I'd feel a lot

better if that thing last night hadn't splashed where it did."

"The bolide," said a voice humorously, "is a free animal."

The discussion went on. Terry saw Deirdre talking to a middle-aged woman

with a splendid sun-tan and a placid expression on her face. Doug and

Tony sat watchfully on the side lines, listening. Doug had been offered,

and had accepted, a sandwich. He ate it methodically.

Terry had a sudden feeling of unreality. Less than half an hour before

he'd been in torment and, but for Deirdre, on his way to death. On the

_Esperance_ there'd been so much that was absorbing in the way of fish

behavior that he'd forgotten some people were interested in other

things. Here a dozen people squabbled over the behavior of a meteorite.

Nothing could be of less consequence to the outside world. But in the

outside world, people argued about baseball, or golf, or politics....

Doug excused himself and slipped outside. Terry joined him there a

little later. Doug was smoking a cigarette, looking at the sky and the

palms.

"Pretty heavy discussion," said Terry.

"It's over my head," said Doug. "I got lonesome. It made me think of my

girl. She likes to talk like this. That's why ..."

He stopped.

"Is there an aqualung outfit on the _Esperance_?" asked Terry.

"Sure! Two or three of them. Mr. Davis had an idea they'd be useful.

Used one of them last week to look at the _Esperance's_ bottom-planks.

Why?"

"I'd like to poke around the bottom of the lagoon a little," said Terry,

with unconscious grimness. "Would you help?"

"Sure!" said Doug.

They went back to the _Esperance_. Doug got out two aqualung outfits.

They checked the valves and tanks and connections. Doug brought out two

spring guns. In half an hour they were in the outboard, headed for what

Doug said was the deepest part of the lagoon.

Arrived there, Terry tested the water with his finger and then went

overside. Instead of a spring gun, he used one of the fish spears that

seemed to be standard equipment for fishing, here. Doug stayed in the

boat to watch.

Terry'd guessed that what he looked for would be in the deepest part of

the lagoon. He was right. Within half an hour he'd speared five fish of

types that had no business being within two thousand fathoms of the

surface. He ignored the lagoon's normal inhabitants. He picked on fish

of a dark-red color, which is predominant in the depths but not

elsewhere. When the fish had extremely small eyes or extremely large

ones, he hunted them determinedly, knowing they were deep-sea fish. He

caught five, which was a good haul, even considering his previous

suspicions.

Doug inspected the catch as the outboard went back to the yacht. Terry

replaced his spear under the gunwale.

"They're queer fish," observed Doug. "I wouldn't want to eat them."

"Neither would I," agreed Terry. "But I feel a certain sympathy for

them. I think we've shared an experience."

He did. Fish so far from their normal environment would not have

migrated unless they'd been forced to. So these fish must have been

driven up from the blissful utter blackness of the abyss, which was

their habitat. He had a vivid memory of the kind of urging they'd

received, because of his recent swim outside the reef opening. That was

the experience he believed they shared.

He got his catch onto the _Esperance's_ deck and found some sharp knives

in the galley, while Doug put the aqualungs away. When Doug came

abovedecks again, he looked distastefully at the work Terry had

undertaken.

"Do you like to do that sort of thing?" he asked.

"Hardly!" said Terry. "But I want to get it done."

Doug watched for a moment or two.

"I'm pretty keen about poetry. Sometimes I feel I've got to sweat over

a poem that I need to get written. It's hard work. There's no real sense

to it. But I feel it's got to be done. I guess that's the way you feel

now."

"Perhaps," said Terry.

It wouldn't have occurred to him to liken the writing of verses to the

dissection of dead deep-sea fish, but Doug had a point. He went away

presently, and Terry completed the highly unpleasant task. He had just

finished flushing the deck clean when Deirdre came back from the

tracking station. He was already at work on the recorder when she

stepped onto the deck.

"You didn't stay," said Deirdre. "I was waiting for a chance to tell my

father about the hum outside the lagoon, but he was as deep in the

meteor argument as any of them. I still haven't told him."

"There's something else to tell him now," Terry remarked. "I went down

with an aqualung. Doug was standing by," he added at her gesture of

protest, "and speared some fish that don't belong here. I've dissected

them. Their swim bladders had been very skillfully punctured, so if they

went or were driven into lesser pressure, they'd leak instead of

bursting. That's how they survived coming up from the depths. But the

main thing is this."

He held out a small plastic object in his hand. It was about an inch in

diameter and two in length, and there were inclusions in the clear

material. There were plates and threads of metal. They had that look of

mysterious purpose that highly-developed technical devices have.

"This was fastened to the fin of a fish that belongs as far down as a

fish can go," he said. "I've found out one of its purposes. When it is

in the water, it makes a sound more acute than a whistle every time

another sound strikes it. Try that on your piano!"

Deirdre stared.

"I'm saying," he repeated, "that it takes in one sound and gives out

another. It's ... it could be a relay. What is that for? What's it all

about? What does it mean? And I ask just those questions because I don't

dare ask who and why!"

"What ... what will you do?" asked Deirdre absurdly.

"I've no idea," Terry told her. "I've got a feeling that the wise thing

to do would be to settle down somewhere and buy a shop, and forget all

this. If I don't think about it, maybe it'll go away."

"I'll get my father and see what he says."

"Tell him," commanded Terry, "that I want to try out my fish-driving

horn. I'd like to have witnesses. If this foolishness has to be reported

to somebody, we need evidence of the facts. I want to drive fish and see

how many deep-sea ones there are in this lagoon, and how many of them

have spy-devices on them."

Deirdre turned away. Then she turned back.

"Spy-dev--"

"I slipped," said Terry. "I shouldn't have said that. Forget it. Just

tell your father I have an extremely urgent impulse to drive fish, and

would he come and help."

Deirdre looked at him strangely, and went onto the wharf to search for

her father.

Terry paced back and forth on the _Esperance's_ deck. In a few minutes

Davis and the crew-cuts appeared with Deirdre. But they were not alone.

Straggling behind them came nearly all the personnel of the tracking

station. There would be somebody on official duty, of course. But here

was the bespectacled Dr. Morton; the bald young man who'd offered Terry

beer; and the installation cook; a typist, and specialists in radar and

other abstruse subjects.

Deirdre said, "I told them about the fish-driving business and they want

to see. They stopped arguing about last night's bolide to take ringside

seats. All right?"

Terry shrugged. He had the recorder already set up. He'd taken a section

of the tape made where the sea was bright, at the place where the

loudest of the unpleasant humming noise was recorded. He'd made a loop

of it so it would play over and over.

He played the much-amplified sound through the underwater horn held in

the air. The result was a raucous bellowing noise. He lowered it into

the water. The horn touched the surface and went under.

Instantly, the fish of the lagoon seemed to go crazy. All the surface

broke and writhed and splashed. There was an incredible number of fish.

Terry turned the horn on one side. In this way, not all the water was

filled with the intolerable noise, but only a net-like beam of it raced

across the water. Within that line the fish continued to leap

frenziedly. The rest of the lagoon suddenly quieted down. In a little

while the beam's space, also, grew quiet. But that was because the fish

that had been previously caught in it had escaped.

"I'm afraid," said Terry, "that this isn't going to be very

entertaining. I'm going to sweep the beam across the lagoon, pushing the

fish ahead of it, until I should have them all in one small area."

It was curious that he felt uncomfortable as he set about his task. But

he'd experienced the sensation this sound produced. And it was not very

pleasant.

He turned the beam around, slightly. Again, there were sudden

splashings. They died away. He turned the beam again. It was a nasty,

snarling vibration in the water. So far as fish were concerned, it was

more like a wall than a net, because not even the tiniest living

creature could penetrate it. Not only fish fled before it. Shrimps and

crabs and all types of crustaceans jerked and crawled and swam ahead of

its motion. Jellyfish writhed when it touched them. Sea cucumbers

contorted themselves. Everything that lived in the lagoon and could swim

or crawl or writhe moved before the invisible barrier. Presently, the

effect of crowding could be seen, and fish began to leap out of water.

"This is a great advance in civilization," said Dr. Morton. "Men

invented guns and destroyed the buffalo and the passenger pigeon! You

may have made it possible to depopulate the sea!"

Terry did not answer. The morning sun shone brightly, a gentle breeze

made ripplings on the lagoon, the palms waved their fronds in languid

gestures, and the surf could be heard booming and splashing on the outer

reef. And about two dozen people stood on the wharf or on the

_Esperance's_ deck and watched a spliced section of recorder-tape go

through and through a recorder, which was set to make a sound underwater

that could not be heard by the people above.

The fish of the lagoon had crowded themselves into a minor embayment of

the shore. There were innumerable leapings there.

"There should be plenty of fish collected now," said Terry

distastefully. "I certainly can't herd them ashore."

The outboard boat pushed away from the yacht, its motor roaring. It

reached the area in which the water seemed to seethe and surge with the

motion of densely-crowded swimming creatures. The people in the boat

examined the surrounding water, then the boat came back at top speed.

"They're there!" called Davis. "And thick enough to walk on! I clearly

saw some freaks that must come up from the bottom! We want to collect

them!"

"I speared five just now," Terry told him, "and one of them was wearing

this."

He held up the plastic object he'd found. There was silence for a

moment. Then Dr. Morton said briskly, "We'll want fish spears. We'll

take all the boats and go after some more of these piscatory oddities.

Who's best with a spear?"

Davis would go. He could use the two fish spears that were standard

equipment for the outboard. The staff of the tracking station scattered

to launch other boats. Only Terry and Deirdre remained on the

_Esperance_. It was necessary for someone to stand by the recorder.

Boats moved away across the water. One stout member of the island's

staff trudged along the shore.

"You're driving them," said Deirdre. "You are right."

"I wish I weren't," said Terry.

"Why?"

"You know how these weird fish got here," he said impatiently. "They

were driven here. You know how they've been kept here. I experienced

that! I told you why they didn't die when they came up from thousands of

fathoms! Now, what's the only possible purpose for their being here? Put

it more scientifically! What is the consequence of these happenings, so

that to some biological entity it would be a favorable happening?" His

tone was sardonic, at the end.

"I don't know."

"I hope I don't either," said Terry dourly.

He was in no amiable mood. He'd made too many guesses like those Davis

had mentioned. He was beginning to have less and less hope that they

were untrue. Each new development made any imaginable cause of these

events just so much more appalling to think about.

In an hour, three boats came back from the small bay into which all the

fish of the lagoon had been crowded. Terry turned off the underwater

horn. A stout man walked slowly along the shore with a heavy burden of

known edible fish. He was the island's cook, and he had speared them

from the beach. The boats, altogether, had speared and captured not less

than sixty specimens of fish normally found only many thousand feet

below the ocean's surface. Upon inspection, all of them were found to

have deftly punctured swim bladders, punctured with so slender a barb

that the opening would close by itself, except when serving for the

release of intolerably expanding gas.

Before noon, seven more plastic objects had been found among the

deep-sea fish. Three seemed identical to the one Terry had found. Two

others were identical to each other but of a different kind, and the

last two were of two different types altogether. Only those like the one

tested by Terry seemed sensitive to sounds, which they changed into

other sounds at a twenty-thousand-cycle frequency, or higher. The rest

did nothing that could be detected.

During the afternoon, news came to distract the absorption of the

tracking station staff in the lagoon's fish. The short-wave operator

came running to the wharf, waving a written message. The deck of the

_Esperance_ was not a pretty sight, just then, with the dissection that

had been taking place on it. Jug was beginning to flush the debris

overside.

The short-wave operator arrived. Dr. Morton read the message. He raised

his voice.

"Here's a fancy one!" he told the assembled company. "Space-radar's

picked up a new object coming in from nowhere. It will probably orbit

once before it hits the air and burns. By the line of motion it should

pass nearly overhead here. We're alerted to get it under observation

and watch it!" He waved the message in a large gesture. "We've got to

get ourselves set up! The argument on the path of last night's bolide

and why it fell where it did is again in order. We'll see what we can do

about computing the fall-point of this!"

He headed for the shore. The staff followed, babbling. Somebody's

mathematics would be verified, and with it his views on the possible

effects of terrestrial magnetism on objects approaching the earth.

"We ought to get these plastic things to Manila," Davis said slowly.

"They need to be compared to others. But I think we'll wait and see this

bolide first."

A heated argument started in the tracking station staff. From Dr. Morton

downward, almost to the station's cook, the most varied predictions were

made. The official computation from Washington, made from the observed

course and height and speed, predicted that the bolide would land

somewhere in the South Pacific. Dr. Morton predicted a fall in the China

Sea, within a certain precisely stated number of miles from Thrawn

Island. Other predictions varied.

At exactly fourteen minutes after eight--a time way ahead of the

official schedule but exactly as Dr. Morton had predicted--the bolide

passed overhead. It was an amazing spectacle. It left a trail of flame

behind, across thirty degrees of sky. It went on and on....

Less than ten minutes later the short-wave radio informed the island

that the shooting star had been seen to fall in the sea. It had been

observed by a plane which was then circling over the area in which the

_Esperance_ had encountered the circle of shining sea. The plane was

there to see if the phenomenon would occur again. It didn't.

But the plane saw the bolide as it struck the sea, and huge masses of

steam and spray arose. The bolide was not white-hot, then, as when it

passed over Thrawn Island. It was barely of dull-red brightness. It hit

the sea and sank, leaving steam behind.

The water was forty-five hundred fathoms deep at that point.

_Six_

Fourteen hours later the _Esperance_ made ready to sail from Thrawn

Island. Her purpose was to carry the plastic objects to Manila, where

they would be turned over to specialized laboratories to be studied.

Five such objects had been found before: one in the Thrawn Island

lagoon, while the satellite-tracking station was under construction, and

four attached to exotic fish brought to market by the commercial fishing

boat _La Rubia_. Now there were eight more, of four different kinds. To

the laboratories would go Terry's observation that one kind of these

objects absorbed sound at audible frequencies and retransmitted it at

much higher ones, but only under water. All this was very interesting

and very puzzling.

But a serious disturbance had arisen at the tracking station.

Dr. Morton came to the _Esperance_ before her departure. He had a

problem. He'd predicted to the minute, and almost to the mile, the

landing of the bolide of the night before. That was the first accurate

prediction of the kind in history. But his forecast stood alone in its

precision. Nobody else had even come near being right. Now he was being

insistently queried by astronomers the world over. They wanted to know

how he'd done it. In particular, they wanted to know how he'd figured

that the bolide would lose just so many feet per second velocity,

neither more nor less, in a three-quarter orbit around the world. Nobody

else had such a figure in his equation for the landing spot. Dr. Morton

had. His prediction had been exact. Where did he get that necessary but

inexplicable figure?

He beckoned Davis and Terry to go below with him, in the _Esperance's_

after cabin. Terry hesitated.

"You may as well hear my troubles," said Morton vexedly. "You're largely

responsible for them."

Terry followed uneasily. He didn't see how Dr. Morton could hold them

responsible. He had guarded his own guesses about the _Esperance's_

discoveries against even the slightest expression. He couldn't let

himself believe in their correctness, but he was appalled at the

inadequacy of all other explanations of past events.

"In sixteen months," said Morton annoyedly, down below, "we've spotted

six bolides coming in to land in the Luzon Deep. That's out of all

reason! Of course, it could be a mathematical series of wildly unlikely

coincidences, such as probability says may happen sometimes. Up to last

night that seemed to be a possible explanation."

Davis nodded. His expression was odd.

"But now," said Morton somehow indignantly, "that's ruled out! It's

ruled out by last night's bolide, and yesterday's fishing experiment,

and that business of the shining sea, plus those damned plastic gadgets

and deep sea fish thriving in shallow water! There's no reasonable

explanation for such things, and they're not mere coincidences!"

"I'm afraid," admitted Davis, "that they're not."

"The obvious explanation," said Morton doggedly, "I refuse to name or

consider. But nevertheless the question is not whether a theory or an

explanation is unlikely or not. The question is whether it's true!"

Davis nodded. Terry had to agree. But the way people are trained in

modern times puts a great emphasis on reason, often at the expense of

fact. Terry felt the customary civilized reluctance to accept a

statistically improbable idea.

"I'm on a spot," fumed Morton. "I calculated that the damned bolide

would slow after it went into orbit around the earth. I calculated that

it would slow exactly so much. Do you want to know how I figured how

much it should slow down? I'll tell you! I calculated exactly how much

it would have to slow to be able to fall into the Luzon Deep! It did

slow. It did fall there. But how am I going to explain that to

Washington?"

Terry suddenly felt a warm sympathy for Morton. It is bad enough to

dispute with oneself when something incredible happens. But Dr. Morton

had gone out on a limb. He'd been caught psychologically naked telling

the truth, and now he was asked to explain it. And he couldn't.

"This thing has got to come to a head!" he said angrily. "Sooner or

later they'll find out that I don't calculate where it'll land by its

behavior in space but by its landing spot! Davis, you've talked about

stirring something up. For Heaven's sake, do it! You may save my

reputation! And you...."

"I'll try to think of something," said Davis reservedly.

"I've got to have proof that my suspicions are right or wrong before I'm

ruined. I know what you're planning to do. Do it! Is there anything that

can be done here to help?"

Davis spread out his hands helplessly. But Terry said, "Yes. Send a boat

every so often to listen at the gap in the reef. Put an oar overboard

and put your ear to the handle. You should hear the underwater hum, if

it's still there. It was there this morning."

Morton looked at him suspiciously.

"Why check on it? Should it change?"

"Perhaps," said Terry. "We've speared most of the deep-sea fish in the

lagoon. Maybe we've interfered with ... the reports from the plastic

objects, telling what was happening up here. There may be a reaction. If

so, most likely the humming will stop, and after a longer or shorter

time begin again. And then, if my guess is right, there'll be more

deep-sea creatures in the lagoon."

"Ha," said Morton. "I think you and I have the same kind of delusions!

All right. I'll see that that's done. You two do the rest."

He went abovedecks. When Terry got on deck, Dr. Morton's angular figure

was already marching along the wharf to the shore.

There was no ceremony of departure. The _Esperance_ cast off and her

engine started. She moved toward the lagoon entrance under power only,

but her sails were hoisted as she floated on, and Jug Bell was trimming

the jib when she cleared the opening to the sea.

The humming in the water was still audible to the submarine ear, close

to the land. It occurred to Terry to take a bearing on the source of the

sound, noting both the compass direction and the vertical angle from

the reef. If his vertical-angle reading was accurate, a line from the

reef to the source of the sound would touch the bottom at twenty-seven

thousand feet down, between four and five miles away.

The _Esperance_ sailed on. The humming duly faded away. Terry left the

recorder picking up undersea sounds, without recording them. It relayed

the underwater sounds to the people on deck. It was in Terry's mind to

keep at least half an ear cocked to it, in case the mooing sounds, heard

and recorded elsewhere, should come again.

They did not. The _Esperance_ went methodically on her way, headed south

by east, under sail. A slowly swaying horizon of unbroken sea was all

about. There was nothing in the least unusual or mysterious to be seen

anywhere.

Presently, Terry found himself in conversation with Deirdre, and the

world seemed so blatantly normal that their talk dodged all unusual

trends. They talked about their childhoods, about things they had done

and places they had seen.

At about four in the afternoon Nick bellowed, "_Thar she blows!_" in a

fine attempt at proper whaling ship style, and all the _Esperance's_

company joined to watch a spouting far ahead. The yacht changed course a

little, and presently reached a pod of sperm whales at the surface. The

huge dark bodies moved leisurely through the water. Jud displayed great

erudition on the subject and explained in detail how their spouting

proved them to be sperm whales. Deirdre pointed out a baby whale close

beside a larger one.

They sailed on, leaving the whales behind. The crew-cuts, inevitably,

argued about them. They canvassed all the information and misinformation

they possessed and came up with a heated discussion about whales, how

they can swim down to the enormous depths without suffering from the

bends on rising again. Then the conversation turned to the food they

eat. Whalers, in the old days, had found snouts of squids and undigested

sections of squids' tentacles in the stomachs of harpooned sperm whales.

There were reports of sections of tentacles four feet thick, implying a

startling total size, all of which proved that the whales had been at

the bottom of the ocean, where such gigantic squids can be found. These

were the reports of reliable whaling skippers. Certainly the scars made

by the tentacular arms of huge squids, indicating battle, have been

found on the skin of sperm whales, and there have been reports of

battles on the surface between whales and squids of sizes most

naturalists would be unwilling to certify. In such cases it was assumed

that the squids had been attacked at the bottom of the sea and had

followed the whale to the surface when it came up in need of air.

Certainly only an enormous squid would be able to sustain a battle with

a whale.

Terry listened to the discussion. Everybody had his own opinion.

"You'd never settle the argument, unless you could put a camera and a

flash gun on a whale and get an instrument-report from it."

Which was not a new idea, of course. But it was curious that the thought

of sending self-reporting instruments down to the bottom of the sea had

been suggested by his own suspicion that similar instruments had been

sent up from below. Sounding lines had been lowered with thermometers

and nets and sampling machines. Core-takers had been dropped to get

samplings of abyssal mud. But tethered instrumentation is never more

than so useful.

Deirdre said something. Terry realized that she'd repeated it. He'd

become absorbed in the possibilities of instrument-reporting from the

surface to the depths and back again.

"You're not listening," protested Deirdre. "I'm talking about the

bathyscaphe that ought to be in Manila any day now."

"I'm trying to picture myself going down in a bathyscaphe," said Terry

hastily. "I don't think I'd like it."

A bathyscaphe is a metal sphere with walls and windows of enormous

thickness, hung from a metal balloon filled with gasoline for flotation.

It is lowered to appalling depths with the help of heavy ballast, and is

equipped with electric motors for independent motion. It carries

powerful electric reflectors which allow as much as thirty or forty feet

of visibility. It rises to the surface again when its ballast is

dumped. There are only three such undersea exploring devices in the

whole world.

"I'm not at all sure you wouldn't like it," said Deirdre.

Terry scowled at his own thoughts. There are opinions a man holds firmly

without ever being aware of them, unless they are challenged, and if

that happens, he is deeply suspicious of the challenge because it

suggests that his opinion needs to be re-examined. Terry had been

gathering scraps of information here, and unquestionable items there,

resisting a conclusion all the while.

It seemed fantastic to think that the plastic objects carried by

deep-sea fish out of their natural environment were actually man-made

instruments--telemetering apparatus closely comparable to the devices

used to transmit information from outer space. It was wildly imaginative

to suppose that they transmitted information from the water surface to

the depths of the ocean; that fish had been driven up from the abyss in

order to report what went on at the surface. Report to whom? It was the

most fantastic of fantasies to think that there was curiosity, in the

Luzon Deep, about the manners and customs of the inhabitants of the

surface waters and of those areas not covered by the sea.

But Terry stopped short. There were limits to the ideas he would allow

his brain to think about.

Deirdre walked away, and he assured himself he never thought of anything

so ridiculous as the conclusions he had just reached. Presently, dinner

was served, and Terry painstakingly acted like a perfectly rational

person. After dinner Davis, as usual, settled himself down to enjoy a

program of symphonic music from San Francisco, many thousands of miles

away. And Deirdre vanished from sight again.

Later on Terry found himself alone on the _Esperance's_ deck, except for

Nick at the wheel--a mere dark figure seen only by the light of the

binnacle lamp. There was a diffused, faint glow coming from the

after-cabin hatch. Up forward, one of the crew-cuts plucked a guitar,

and Terry could imagine Doug dourly trying to read poetry despite the

noise. The sails were black against the sky. The deck was darker than

the sea.

Terry's guesses haunted him. He assured himself that he did not

entertain them even for an instant. They were absurd! A part of his mind

argued speciously that if they were absurd there was no reason not to

test them. If he was afraid to try, it would imply that at least part of

him believed them.

He picked up one of the plastic objects, and moved the recorder close to

the lee rail. It still transmitted faithfully, at minimum volume, the

washing of the waves as heard from beneath, and occasional small sounds

from living creatures, generally far away in the sea. Heeled over as the

_Esperance_ was, his hand could reach down into the rushing waters

overside.

He came to a resolution. He felt foolish, but by now he was determined

to try an experiment. Tiny light-blue sparks flashed where the water

raced past the yacht's planking. When he dipped his hand, water piled up

against his wrist and a streak of brightness trailed away behind.

He tapped the plastic object against the hull. One tap, two taps, three

taps, four taps. Then five, six, seven, eight. He went back to one. One

tap, two, and three and four. Five and six and seven and eight.

The recorder gave out the tappings the underwater microphone had picked

up. It seemed to Terry that the loudspeaker struggled to emit the

shrillest imaginable sounds in strict synchrony with the tappings.

Then Deirdre's voice came quietly, very near.

"I don't think," she said evenly, "that that's a fair thing to do."

He'd been bent over the rail in an awkward position. He straightened up,

guiltily.

"I know it's nonsense, but I was ... ashamed to admit ..."

"To admit," Deirdre concluded for him, "that by tapping numbers with a

plastic spy-device, you hoped to say to whom it might concern that we've

found a communicator, and we know what it is, and we're trying to get in

touch with the intelligent creatures who made it."

To hear his own self-denied guesses spoken aloud was appalling. Terry

instantly disbelieved them entirely.

"It's ridiculous, of course," he protested. "It's childish...."

"But it could be true," said Deirdre. "And, if true, it could be

dangerous. Suppose whatever put those plastic gadgets on the fish

doesn't want to be communicated with? Suppose it feels that it should

defend the secret of its existence by killing those who suspect it? I

wasn't spying on you," she added. "I heard the tappings down below."

Then she was gone. He saw the interruption in the light from the

after-cabin hatch as she went below.

He was suddenly filled with horror at the idea that if his guesses did

prove to be right, he might have endangered Deirdre. And then he ceased

to feel foolish. He felt like a criminal instead.

For a long, long time he listened with desperate intensity to the

recorder, lest he hear some reply to his signals.

But no answer came. The sounds from undersea remained utterly

commonplace.

When morning arrived he was in a state of desperate gloom. At breakfast

Deirdre acted as if she considered the incident closed. And, such being

the nature of men, Terry felt worse than before.

He was not wholly at ease again, even when that afternoon the

_Esperance_ sailed in past Cavite and Corregidor and into Manila Bay. A

new ship was at anchor in the harbor. It was a stubby, stocky ship which

Davis regarded with interest.

"That's the _Pelorus_," he told Terry as the yacht passed within a mile,

on the way to her former anchorage. "She's the hydrographic ship with

the bathyscaphe on board. We'll visit her. I'll get Nick to call her on

short-wave."

He went forward, where Nick was making ready to drop the anchor. Davis

took over the chore, and Nick went below.

"Are you going ashore?" asked Deirdre.