connected like two halves of a swing, one side moving up when the other moved down, or like swings or like cogs and pendulums inside a clock, only without the cogs, just with the push.

It wasn't adding or multiplication, and it used letters instead of numbers, but Ronny knew it was some kind of arithmetic.

And he wasn't Ronny.

He was an old man, teaching young men, and the old man did not know about Ronny. He thought sadly how little he would be able to convey to the young men, and he remembered more, trying to sum long memories and much living into a few direct thoughts. And Ronny was the old man and himself, both at once.

t was too intense. Part of Ronny wanted to escape and be alone, and that part withdrew and wanted to play something. Ronny sat in the grass and played with his toes like a much younger child.

Part of Ronny that was Doctor Revert Purcell sat on the edge of a prison cot, concentrating on secret unpublished equations of biogenic stability which he wanted to pass on to the responsible hands of young researchers in the concealed-research chain. He was using the way of thinking which they had told him was the telepathic sending of ideas to anyone ready to receive. It was odd that he himself could never tell when he was sending. Probably a matter of age. They had started trying to teach him when he was already too old for anything so different.

The water tap, four feet away, was dripping steadily, and it was hard for Purcell to concentrate, so intense was his thirst. He wondered if he could gather strength to walk that far. He was sitting up and that was good, but the struggle to raise himself that far had left him dizzy and trembling. If he tried to stand, the effort would surely interrupt his transmitting of equations and all the data he had not sent yet.

Would the man with the keys who looked in the door twice a day care whether Purcell died with dignity? He was the only audience, and his expression never changed when Purcell asked him to point out to the authorities that he was not being given anything to eat. It was funny to Purcell to find that he wanted the respect of any audience to his dying, even of a man without response who treated him as if he were already a corpse.

Perhaps the man would respond if Purcell said, "I have changed my mind. I will tell."

But if he said that, he would lose his own respect.

At the biochemists' and bio-physicists' convention, the reporter had asked him if any of his researches could be applied to warfare.

He had answered with no feeling of danger, knowing that what he did was common practice among research men, sure that it was an unchallengeable right.

"Some of them can, but those I keep to myself."

The reporter remained dead-pan. "For instance?"

"Well, I have to choose something that won't reveal how it's done now, but—ah—for example, a way of cheaply mass-producing specific antitoxins against any germ. It sounds harmless if you don't think about it, but actually it would make germ warfare the most deadly and inexpensive weapon yet developed, for it would make it possible to prevent the backspread of contagion into a country's own troops, without much expense. There would be hell to pay if anyone ever let that out." Then he had added, trying to get the reporter to understand enough to change his cynical unimpressed expression, "You understand, germs are cheap—there would be a new plague to spread every time some pipsqueak biologist mutated a new germ. It isn't even expensive or difficult, as atom bombs are."

The headline was: "Scientist Refuses to Give Secret of Weapon to Government."

overnment men came and