Rumors blanketed the country like a fog, and people everywhere became uneasy. There were no deaths from the illness, but the very idea that an infectious disease could flare up unpredictably all over the nation, out of control, was frightening. It was said that the disease had been beamed to Earth by alien enemies from space; that all its victims became sterile; or that their minds were permanently damaged. It was also said, though people laughed even as they repeated the rumor, that if you once had Blue Martian Fever you'd become immortal. This particular theory had been clearly traced to the ravings of a red-haired madwoman who was confined to Psycho-detention, but still it was too ridiculous not to repeat. For a week, comedians rang a hundred changes on the basic joke: Wife: Drop dead! Husband: I can't. I've had Blue Martian. The unrest became so great that Leader Marley himself appeared on the telecaster to reassure the nation. He was an impressive figure on the lighted screen, resting solid and at ease in a leather chair, raising his massive black head, lifting his big hand to gesture as his rich voice rolled out. "You have nothing to fear," he said. "Under your beneficent Leaders, infectious disease has been wiped out many years ago. BureauMed informs me that these scattered cases of Blue Martian fever have been caused by the escape of a few _Fafli_ insects, which have, since then, been isolated and destroyed. The illness has no serious after-effects. And as for the rumors that it confers immortality--" He allowed his face to break into a pitying smile as he slowly shook his head, looking regretful and yet somehow amused. "Those who continue to spread gossip about the fever will only reveal themselves as either psychotics or traitors. Whichever they are, they will be isolated for the good of our society." The effect of his words was somewhat diminished by the brief glimpse people had of Dr. Lanza, who reached a hand to help the Leader rise. For Dr. Lanza wore an anxious frown, and his face was thin with worry. In spite of numerous arrests, the rumors continued. For two weeks sporadic outbreaks of the fever occurred, and then, abruptly, they ceased. * * * * * It was more than a week after the last case had been reported that David sat in his basement laboratory beside the opened mouse cage, watching with wry affection as the furry creatures crawled over his hand. These were historic mice, he reflected, whose reactions to SDE had opened up a new world, a world which he must somehow help to make better than the present one.