“The other day, yes. The colts—”

“Uh-huh. There’ve been five colts born of eleven mares in the last year. Two of them were so deformed they died in a week, another in a few months. One of the two left has cloven hoofs and almost no teeth. The last one looked normal—so far. One out of eleven, Drummond.”

“Were those horses near a radioactive area?”

“They must have been. They were rounded up wherever found and brought here. The stallion was caught near the site of Portland, I know. But if he were the only one with mutated genes, it would hardly show in the first generation, would it? I understand nearly all mutations are Mendelian recessives. Even if there were one dominant, it would show in all the colts, but none of these looked alike.”

“Hm-m-m—I don’t know much about genetics, but I do know hard radiation, or rather the secondary charged particles it produces will cause mutation. Only mutants are rare, and tend to fall into certain patterns—”

“Were rare!” Suddenly Robinson was grim, something coldly frightened in his eyes. “Haven’t you noticed the animals and plants? They’re fewer than formerly, and…well, I’ve not kept count, but at least half those seen or killed have something wrong, internally or externally.”

Drummond drew heavily on his pipe. He needed something to hang onto, in a new storm of insanity. Very quietly, he said:

“In my college biology course, they told me the vast majority of mutations are unfavorable. More ways of not doing something than of doing it. Radiation might sterilize an animal, or might produce several degrees of genetic change. You could have a mutation so violently lethal the possessor never gets born, or soon dies. You could have all kinds of more or less handicapping factors, or just random changes not making much difference one way or the other. Or in a few cases you might get something actually favorable, but you couldn’t really say the possessor is a true member of the species. And favorable mutations themselves usually involve a price in the partial or total loss of some other function.”

“Right.” Robinson nodded heavily, “One of your jobs on the census will be to try and locate any and all who know genetics, and send them here. But your real task, which only you and I and a couple of others must know about, the job overriding all other considerations, will be to find the human mutants.”

Drummond’s throat was dry. “There’ve been a lot of them?” he whispered.

“Yes. But we don’t know how many or where. We only know about those people who live near an army post, or have some other fairly regular intercourse with us, and they’re only a few thousand all told. Among them, the birth rate has gone down to about half the prewar ratio. And over half the births they do have are abnormal.”

“Over half—”

“Yeah. Of course, the violently different ones soon die, or are put in an institution we’ve set up in the Alleghenies. But what can we do with viable forms, if their parents still love them? A kid with deformed or missing or abortive organs, twisted internal structure, a tail, or something even worse…well, it’ll have a tough time in life, but it can generally survive. And perpetuate itself—”