Zaino tried. Hour after hour he juggled from one band to another. Once
he had Hargedon stop while he went out to attach a makeshift antenna
which, he hoped, would change his output from broadcast to some sort
of beam; after this he kept probing the sky with the "beam," first
listening to the _Albireo's_ broadcast in an effort to find projecting
wisps of ionosphere and then, whenever he thought he had one, switching
on his transmitter and driving his own message at it.
Not once did he complain about lack of equipment or remark how much
better he could do once he was back at the ship.
Hargedon's silence began to carry an undercurrent of approval not
usual in people who spent much time with Zaino. The technician made no
further reference to the suggestion of switching drivers. They came
in sight of the _Albireo_ and doubled the chasm with Hargedon still at
the wheel, Zaino still at his radio and both of them still uncertain
whether any of the calls had gotten through.
Both had to admit, even before they could see the ship, that Burkett
had had a right to be impressed.
The smoke column showed starkly against the sky, blowing back over the
tractor and blocking the sunlight which would otherwise have glared
into the driver's eyes. Fine particles fell from it in a steady shower;
looking back, the men could see tracks left by their vehicle in the
deposit which had already fallen.
As they approached the ship the dark pillar grew denser and narrower,
while the particles raining from it became coarser. In some places the
ash was drifting into fairly deep piles, giving Hargedon some anxiety
about possible concealed cracks. The last part of the trip, along the
edge of the great chasm and around its end, was really dangerous;
cracks running from its sides were definitely spreading. The two men
reached the _Albireo_ later than Hargedon had promised, and found
Burkett waiting impatiently with a pile of apparatus beside her.
She didn't wait for them to get out before starting to organize.
"There isn't much here. We'll take off just enough of what you're
carrying to make room for this. No--wait. I'll have to check some of
your equipment; I'm going to need one of Milt Schlossberg's gadget's, I
think, so leave that on. We'll take--"
"Excuse me, Doctor," cut in Hargedon. "Our suits need servicing, or at
least mine will if you want me to drive you. Perhaps Arnie can help you
load for a while, if you don't think it's too important for him to get
at the radio--"
"Of course. Excuse me. I should have had someone out here to help me
with this. You two go on in. Ren, please get back as soon as you can. I
can do the work here; none of this stuff is very heavy."
Zaino hesitated as he swung out of the cab. True, there wasn't too
much to be moved, and it wasn't very heavy in Mercury's gravity,
and he really should be at the radio; but the thirty-nine-year-old
mineralogist was a middle-aged lady by his standards, and shouldn't be
allowed to carry heavy packages....
"Get along, Arnie!" the middle-aged lady interrupted this train of
thought. "Eric and Eileen are getting farther away and harder to reach
every second you dawdle!"
* * * * *
He got, though he couldn't help looking northeast as he went rather
than where he was going.
The towering menace in that direction would have claimed anyone's
attention. The pillar of sable ash was rising straighter, as though
the wind were having less effect on it. An equally black cone had
risen into sight beyond Northeast Spur--a cone that must have grown
to some two thousand feet in roughly ten hours. It had far steeper
sides than the cinder mounds near it; it couldn't be made of the same
loose ash. Perhaps it consisted of half-melted particles which were
fusing together as they fell--that might be what Burkett had meant by
"spatter-cone." Still, if that were the case, the material fountaining
from the cone's top should be lighting the plain with its incandescence
rather than casting an inky shadow for its entire height.
Well, that was a problem for the geologists; Zaino climbed aboard and
settled to his task.
The trouble was that he could do very little more here than he could
in the tractor. He could have improvised longer-wave transmitting
coils whose radiations would have diffracted a little more effectively
beyond the horizon, but the receiver on the missing vehicle would
not have detected them. He had more power at his disposal, but could
only beam it into empty space with his better antennae. He had better
equipment for locating any projecting wisps of charged gas which might
reflect his waves, but he was already located under a solid roof of the
stuff--the _Albireo_ was technically on Brightside. Bouncing his beam
from this layer still didn't give him the range he needed, as he had
found both by calculation and trial.
What he really needed was a relay satellite. The target was simply too
far around Mercury's sharp curve by now for anything less.
Zaino's final gesture was to set his transmission beam on the lowest
frequency the tractor would pick up, aim it as close to the vehicle's
direction as he could calculate from map and itinerary and set the
recorded return message going. He told Rowson as much.
"Can't think of anything else?" the captain asked. "Well, neither can
I, but of course it's not my field. I'd give a year's pay if I could.
How long before they should be back in range?"
"About four days. A hundred hours, give or take a few. They'll be
heading back anyway by that time."
"Of course. Well, keep trying."
"I am--or rather, the equipment is. I don't see what else I can do
unless a really bright idea should suddenly sprout. Is there anywhere
else I could be useful? I'm as likely to have ideas working as just
sitting."
"We can keep you busy, all right. But how about taking a transmitter up
one of those mountains? That would get your wave farther."
"Not as far as it's going already. I'm bouncing it off the ion layer,
which is higher than any mountain we've seen on Mercury even if it's
nowhere near as high as Earth's."
"Hmph. All right."
"I could help Ren and Dr. Burkett. I could hang on outside the
tractor--"
"They've already gone. You'd better call them, though, and keep a log
of what they do."
"All right." Zaino turned back to his board and with no trouble raised
the tractor carrying Hargedon and the mineralogist. The latter had been
trying to call the _Albireo_ and had some acid comments about radio
operators who slept on the job.
* * * * *
"There's only one of me, and I've been trying to get the Darkside
team," he pointed out. "Have you found anything new about this lava
flood?"
"Flow, not flood," corrected the professional automatically. "We're
not in sight of it yet. We've just rounded the corner that takes us
out of your sight. It's over a mile yet, and a couple of more corners,
before we get to the spot where I left it. Of course, it will be closer
than that by now. It was spreading at perhaps a hundred yards an hour
then. That's one figure we must refine.... Of course, I'll try to get
samples, too. I wish there were some way to get samples of the central
cone. The whole thing is the queerest volcano I've ever heard of. Have
you gotten Eileen started back?"
"Not as far as I can tell. As with your cone samples, there are
practical difficulties," replied Zaino. "I haven't quit yet, though."
"I should think not. If some of us were paid by the idea we'd be pretty
poor, but the perspiration part of genius is open to all of us."
"You mean I should charge a bonus for getting this call through?"
retorted the operator.
Whatever Burkett's reply to this might have been was never learned; her
attention was diverted at that point.
"We've just come in sight of the flow. It's about five hundred yards
ahead. We'll get as close as seems safe, and I'll try to make sure
whether it's really lava or just mud."
"Mud? Is that possible? I thought there wasn't--couldn't be--any water
on this planet!"
"It is, and there probably isn't. The liquid phase of mud doesn't have
to be water, even though it usually is on Earth. Here, for example, it
might conceivably be sulfur."
"But if it's just mud, it wouldn't hurt the ship, would it?"
"Probably not."
"Then why all this fuss about getting the tractors back in a hurry?"
* * * * *
The voice which answered reminded him of another lady in his past, who
had kept him after school for drawing pictures in math class.
"Because in my judgment the flow is far more likely to be lava than
mud, and if I must be wrong I'd rather my error were one that left
us alive. I have no time at the moment to explain the basis of my
judgment. I will be reporting our activities quite steadily from now
on, and would prefer that you not interrupt unless a serious emergency
demands it, or you get a call from Eileen.
"We are about three hundred yards away now. The front is moving about
as fast as before, which suggests that the flow is coming only along
this valley. It's only three or four feet high, so viscosity is very
low or density very high. Probably the former, considering where we
are. It's as black as the smoke column."
"Not glowing?" cut in Zaino thoughtlessly.
"_Black_, I said. Temperature will be easier to measure when we get
closer. The front is nearly straight across the valley, with just a few
lobes projecting ten or twelve yards and one notch where a small spine
is being surrounded. By the way, I trust you're taping all this?" Again
Zaino was reminded of the afternoon after school.
"Yes, Ma'am," he replied. "On my one and only monitor tape."
"Very well. We're stopping near the middle of the valley one hundred
yards from the front. I am getting out, and will walk as close as I
can with a sampler and a radiometer. I assume that the radio equipment
will continue to relay my suit broadcast back to you." Zaino cringed a
little, certain as he was that the tractor's electronic apparatus was
in perfect order.
It struck him that Dr. Burkett was being more snappish than usual. It
never crossed his mind that the woman might be afraid.
"Ren, don't get any closer with the tractor unless I call. I'll get a
set of temperature readings as soon as I'm close enough. Then I'll try
to get a sample. Then I'll come back with that to the tractor, leave it
and the radiometer and get the markers to set out."
"Couldn't I be putting out the markers while you get the sample,
Doctor?"
"You could, but I'd rather you stayed at the wheel." Hargedon made no
answer, and Burkett resumed her description for the record.
"I'm walking toward the front, a good deal faster than it's flowing
toward me. I am now about twenty yards away, and am going to take a set
of radiation-temperature measures." A brief pause. "Readings coming.
Nine sixty. Nine eighty. Nine ninety--that's from the bottom edge near
the spine that's being surrounded. Nine eighty-five--" The voice
droned on until about two dozen readings had been taped. Then, "I'm
going closer now. The sampler is just a ladle on a twelve-foot handle
we improvised, so I'll have to get that close. The stuff is moving
slowly; there should be no trouble. I'm in reach now. The lava is very
liquid; there's no trouble getting the sampler in--or out again--it's
not very dense, either. I'm heading back toward the tractor now. No,
Ren, don't come to meet me."
There was a minute of silence, while Zaino pictured the spacesuited
figure with its awkwardly long burden, walking away from the
creeping menace to the relative safety of the tractor. "It's frozen
solid already; we needn't worry about spilling. The temperature is
about--five eighty. Give me the markers, please."
Another pause, shorter this time. Zaino wondered how much of that
could be laid to a faster walk without the ladle and how much to the
lessening distance between flow and tractor. "I'm tossing the first
marker close to the edge--it's landed less than a foot from the lava.
They're all on a light cord at ten-foot intervals; I'm paying out the
cord as I go back to the tractor. Now we'll stand by and time the
arrival at each marker as well as we can."
"How close are you to the main cone?" asked Zaino.
"Not close enough to see its base, I'm afraid. Or to get a sample of
it, which is worse. We--goodness, what was that?"
Zaino had just time to ask, "What was what?" when he found out.