IV

Norden felt a wave of hate boil up in him, and made no attempt to check

it. As he returned Armsworth's stare his mind reacted to the situation

before he could realize more than a few of the implications.

Obviously, Armsworth was a spy who knew of the work here, and had come

to wreck it. With his rank, it would be easy enough for him to get in.

Also, the man stood there with none of the fear he should have shown on

being discovered, and Norden felt the sick confirmation of his being a

pawn for the Aliens.

But the fact itself gave him some chance. He lifted his arm to the

switch, and then dropped it. "The guards would suspect something if I

cut it off now," he admitted candidly. "Any suggestions?"

"I could kill the lizards, let you discover me, and chase me out to

explode," Armsworth said thoughtfully, without any emotional color to

the suggestion. He shook his head.

"I don't know. It's funny they can't trust you to stall off the Miles

girl and have to send me here. With replacements scarce, I'd hate to

blow up unless it's absolutely necessary."

Then his eyes narrowed in incredulous alarm. "Wait a minute. You

weren't supposed to know my identity."

Norden's hand swept up, hit the light switch. His other arm jerked out

for the big tongs he had noticed. He heard the spy leap, and recoiled

just in time to avoid the rush. His arm came down with the instrument,

and there was a solid thud. When he turned the lights on again,

Armsworth lay on the floor with a gash across his head an inch deep.

For a moment Norden was only aware of his own harsh breathing. Then,

slowly and horribly, the corpse sat up and began hitching along the

floor toward the cage of lizards.

Norden bent, picked up the little cage and swung towards the door.

He took one step forward, stopped abruptly, and bent again. His hand

gripped the collar of the thing on the floor and, straightening, he

heaved it up against the light gravity of the Moon.

The thing sailed across the laboratory, heading toward the rear of the

heavy protogravity generator. Norden cushioned the cage of lizards

against his chest and dropped to the floor in the shelter of the

computer.

There was a blast that nearly ruptured his eardrums and the

accompanying glare of greenish-yellow light burned through his eyelids

into his brain. The floor heaved and shook, while sections of the

curved roof began falling. The air gushed upwards, and the floor jarred

again as the automatic airseal dropped, cutting off other sections.

Norden jumped toward a plainly marked closet, and threw it open. He

yanked down one of the spacesuits stored there for emergency purposes,

thrust the lizard cage inside, closed it, and turned on the oxygen.

Adapted to the thin air of Mars, it seemed likely the animals would

remain alive. He groped about until he located another suit that would

fit, cursed as he found it zippered closed, and finally worked it open.

Once in, he sealed it, and headed toward the personnel lock on the big

emergency airseal.

He got through just as the guards were about to enter in their own

spacesuits, dragging rescue equipment. Miles was with them, waiting

impatiently while Norden slipped his helmet off. "Who was it?" he

demanded.

"Armsworth," Norden told him. "After he passed the fluoroscope test!"

Miles sighed, but there was no surprise. "Damn! I should have had him

checked when he came back from inspecting the other side. They must

have had a spy all ready to make the switch as soon as they got him. Or

maybe the test doesn't mean anything."

The guards had come back. One of them began to report on what they had

seen. Most of the damage had been confined to the roof of the building,

and to the big protogravity generator, which apparently had shielded

the rest of the equipment.

Norden and Pat, who had finally been called, went inside in their suits

to supervise clearing away the debris. Outside, a crew was already

erecting a new roof on the laboratory, using prefab sheets. Aside from

the generator they had never used, nothing irreplaceable had been hurt.

And the two little male lizards were doing well enough. Inside of two

hours the laboratory was back in full operation.

By common consent, Pat and Norden abandoned all idea of sleeping.

Norden started to draw up a list of new tests, and then went back to

the potassium shield. It seemed to produce a very slight quantitative

difference in the reaction of the females. He consulted the vague

speculations in his own works on possible other spectra, and came back.

The trouble was that he wasn't working with any natural phenomenon,

but with life. He grimaced at the twist of his logic, but the sense

remained. Something came into the back of his mind from a phrase in

Hardwick's notes. It teased him, until his mind almost had it, and

then another taboo clamped down on his thoughts.

He fought it out, standing still while Pat stared at him doubtfully.

Twice he could feel himself almost black out, but he tracked the taboo

down in his mind, pursued it into its lair, and strangled it. It died

hard, but left his answer available.

"K-40," he said. His voice was steady, and Pat relaxed, unable to see

the complete fatigue inside him. Disciplining himself seemed to be the

hardest possible task. "Radio-active potassium isotope. It's supposed

to be mixed up somehow with the life processes. Some scientists claim

it's essential to life."

She reached for the phone, and spoke into it briefly. Then there was a

wait, before she handed it over, and a voice came on. "This is General

Dawes at Oak Ridge. Who's calling?"

"William Norden, Project A-sub-zero, Moon Base. I want five pounds of

K-40 up here in four hours. Use my top priority and mark the shipment

for delivery to me only."

There was the usual few seconds of waiting while the message traveled

to Earth, and back. "Five _pounds_?" the voice asked, incredulously.

"Five pounds! And I may want more as fast as it can be gathered."

Pat was on another phone. Before Earth could answer again, there was

a click, and General Miles' voice broke in sharply. "This is Miles,

Dawes. _Give Norden what he wants._"

A sputter of protest began, but it ended abruptly as Miles' voice

reached Earth. The silence was broken by a sigh. "Okay, Norden, we'll

get it to you in four hours somehow."

It arrived in less time, and Norden and Pat began the tricky job of

getting the highly active elements into a container which was both

chemically and radio-actively safe. They clamped it over the cage at

last, and watched the pressure on the female cages.

The results weren't spectacular, but they were unquestionable. And

later, when they had reduced the amount of K-40 to a thin coating, it

still worked. The quantity of potassium made very little difference

beyond a certain minimum.

The effects still weren't good enough. They tried painting various

substances with the chloride of the potassium, with equally good

results and much greater ease of handling. The nitrate was even better

to work with.

But it took them until late that night before they learned that coating

the nitrate over cleaned iron was a major step forward. Until then it

had been all hit and miss, except for vague directional hunches.

Norden looked at Pat, who seemed ready to drop. "Better go back for

some rest," he suggested. She shook her head, but did agree to lie down

while he began re-checking their results to date. Their best efforts

had quieted the excitement of the females by no more than ten percent.

He reduced everything he could to a consistent basis, and added other

formulae which might apply from the incomplete relationship tables

that strove to reconcile the two recognized spectra. Those might also

indicate something about any third spectrum. Either his memory was

coming back or his reading of the books and articles was beginning to

take effect, he was pleased to notice.

Pat worked the computer, which had fortunately suffered only minor

damages, and had been repaired. From the computations, they made the

indicated experiments, and fed the results into the machine. This time,

it gave only seven suggested answers, with a rough weighing of them.

The second one called for one of several organic substances soaked in

potassium ferrocyanide and grounded.

While they waited for the chemistry shed to handle that with due

precautions on the radio-active isotope, they tried the others. One

gave a better than fifty percent reduction, which meant that the

females were only mildly crazy.

"Don't they ever relax?" Pat wondered, unwrapping one of the

sandwiches Miles had ordered sent in to them.

The female sand lizard's libido mattered less than nothing to Norden at

the moment. He was staring at the work he had done in relating hints

and fragments of information with pure hunches to get new facts, and

realizing that he could never have done that, even before the Aliens

had tampered with him. Either he was mysteriously more capable, now

that he'd managed to overcome a few of the taboos in his mind, or

else the loss of so much of his memory had left his thoughts freer to

operate.

"We'll call this the Hardwick spectrum," he decided aloud. "The man was

a crackpot cultist, but he was a genius, all the same. And with this,

we'll pay those damned Aliens back for what they did to him."

"We wouldn't be able to if you hadn't had time to get the males and

yourself into oxygen suits before Armsworth exploded," Pat told him.

"They're the only males left alive, now that Mars has been scoured by

the Aliens."