"Ah"-Benson's lips drew back in a spasmodic smile-"you remember my theory. Yes, I think it was a Martian. Think, man, think! They're coming out in the open now and every piece of information may be vital. We have so little time."

"Why so little time?" David raised himself to one elbow.

"Of course you don't know what's happened since you've been gone, but frankly, Williams, we are all of us in despair now." He held up the gun-like affair in his hand and said bitterly, "Do you know what this is?"

"I've seen you with it before."

"It's my sampling harpoon; it's my own invention. I take it with me when I'm at the storage bins in the city. It shoots a little hollow pellet attached to it by a metal-mesh cord into a bin of, let us say, grain. At a certain time after shooting an opening appears in the front of the pellet long enough to allow the hollow within to become packed with grain. After that the pellet closes again. I drag it back and empty out the random sample it has accumulated. By varying the time after shooting in which the pellet opens, samples can be taken at various depths in the bin."

David said, "That's ingenious, but why are you carrying it now?"

"Because I'm wondering if I oughtn't to throw it into the disposal unit after I leave you. It was my only weapon for fighting the poisoners. It has done me no good so far, and can certainly do me no good In the future."

"What has happened?" David seized the other's shoulder and gripped it hard. "Tell me."

Benson winced at the pain. He said, "Every member of the farming syndicates has received a new letter from whoever is behind the poisoning. There's no doubt that the letters and the poisonings are caused by the same men, or rather, entities. The letters admit it now."

"What do they say?"

Benson shrugged. "What difference do the details make? What it amounts to is a demand for complete surrender on our part or the food-poisoning attacks will be multiplied a thousandfold. I believe it can and will be done, and if that happens, Earth and Mars, the whole system, in fact, will panic."

He rose to Ms feet. ''I've told Makian and Hennes that I believe you, that your Space Ranger is the clue to the whole thing, but they won't believe me. Hennes, 1 think, even suspects that I'm in it with you."

He seemed absorbed in his own wrongs. David said, "How long do we have Benson?"

"Two days. No, that was yesterday. We have thirty-six hours now."

Thirty-six hours!

David would have to work quickly. Very quickly. But maybe there would yet be time. Without knowing it Benson had given him the missing piece to the mystery.

He said, "I don't want Hennes catching me. We've had-words."

"What about Makian? He's on our side, isn't he?"

"I don't know. He stands to be ruined by day after tomorrow. I don't think he has enough spine left to stand up to the fellow. Look, I'd better go. If you think of anything, anything at all, get it to me somehow, will you?"

He held out a hand. David took it briefly, and then Benson was gone.

David sat up in bed. His own uneasiness had grown since he had awakened. His clothes were thrown over a chair at the other end of the room. His boots stood upright by the side of the bed. He had not dared inspect them in Benson's presence; had scarcely dared look at them.

Perhaps, he thought pessimistically, they had not tampered with them. A farmboy's hip boots are inviolate. Stealing from a farmboy's hip boots, next to stealing his sand-car in the open desert, was the unforgivable crime. Even in death, a farmboy's boots were buried with him, with the contents unremoved.

David groped inside the inner pocket of each boot in turn, and his fingers met nothingness. There had been a handkerchief in one, a few odd coins in the other. Undoubtedly they had gone through his clothing; he had expected that. But apparently they had not drawn the line at his boots. He held his breath as his arm dived into the recesses of one boot. The soft leather reached to his armpit and crumpled down as Ms fingers stretched out to the toes. A surge of pure gladness filled him as he felt the soft gauze-like material of the Martian mask.

He had hidden it there on general principles before the bath, but he had not anticipated the Soporite. It was luck, purely, that they had not searched the toes of his boots. He would have to be more careful henceforward.

He put the mask into a boot pocket and clipped it shut. He picked up the boots; they had been polished while he slept, which was good of someone, and showed the almost instinctive respect which the farm-boy had for boots, anyone's boots.

His clothes had been put through the Refresher Spray as well. The shining plastic fibers of which they were composed had a brand-new smell about them. The pockets were all empty, of course, but underneath the chair all the contents were in a careless heap. He sorted them out. Nothing seemed to be missing. Even the handkerchief and coins from his boot pockets were there.

He put on underclothes and socks, the one-piece overall, and then the boots. He was buckling his belt when a brown-bearded farmboy stepped in.

David looked up. He said coldly, "What do you want, Zukis?"

The farmboy said, "Where do you think you're going, Earthie?" His little eyes were glaring viciously, and to David the other's expression was much the same as it had been the first day he had laid eyes on him. David could recall Hennes's sand-car outside the Farm Employment Office, himself just settling into the seat, and the bearded angry face glowering at him, while a weapon fired before he could move to defend himself.

"Nowhere," said David, "that I need ask your permission."

"That so? You're wrong, mister, because you're staying right here. Hennes's orders." Zukis blocked the door with his body. Two blasters were conspicuously displayed at either side of his drooping belt.

Zukis waited. Then, his greasy beard splitting in two as he smiled yellowly, he said, "Think maybe you've changed your mind, Earthie?"

"Maybe," said David. He added, "Someone got in to see me just now. How come? Weren't you watching?"

"Shut up," snarled Zukis.

"Or were you paid off to look the other way for a while? Hennes might not like that."

Zukis spat, missing David's boots by half an inch.

David said, "You want to toss out your blasters and try that again?"

Zukis said, "Just watch out if you want any feeding, Earthie."

He closed and locked the door behind him as he left. A few minutes passed and there was the sound of clattering metal against it as it opened again. Zukis carried a tray. There was the yellow of squash on it and the green of something leafy.

"Vegetable salad," said Zukis. "Good enough for you."

A blackened thumb showed over one end of the tray. The other end balanced upon the back of his wrist so that the farmboy's hand was not visible.

David straightened, leaping to one side, bending his legs under him and bringing them down upon the mattress of the bed. Zukis, caught by surprise, turned in alarm, but David, using the springs of the mattress as extra leverage, launched into the air.

He collided heavily with the farmboy, brought down one hand flatly on the tray, ripping it out of the other's grasp and hurling it to the ground while twining his other hand in the farmboy's beard.

Zukis dropped, yelling hoarsely. David's booted foot came down on the farmboy's hand, the one that had been hidden under the tray. The other's yell be came an agonized scream as the smashed fingers flew open, releasing the cocked blaster they had been holding.

David's hand whipped away from the beard and caught the other's unharmed wrist as it groped for the second blaster. He brought it up roughly, across the prone chest, under the head and out again. He pulled.