On the way he passed close to the control-building of the landing grid. There was a light inside it, too. There were four men on watch. Two remained inside, very, very still, when Calhoun went on. The others seemed to have fled and collapsed in the act. They breathed, to be sure. Their hearts beat solidly. But it would not be possible to rouse them to consciousness. Calhoun didn't get into the ship, though. A chance happening intervened, which seemed an unfavorable one. Its port was locked and his cautious attempt to open it brought a challenge and a blaze of lights. He fled for the side of the landing grid with blaster-bolts searing the ground all about him. Murgatroyd leaped and pranced with him as he ran. VI "The probable complete success of a human enterprise which affects non-co-operating other human beings may be said to vary inversely as the fourth power of the number of favorable happenings necessary for complete success. This formula is admittedly empirical, but its accordance with observation is remarkably close. In practice, the probability of absolute, total success in any undertaking is negligible. For this reason, mathematics and sanity alike counsel the avoidance of complex plannings, and most especially of plans which must succeed totally to succeed at all." _Probability and Human Conduct_ Fitzgerald When morning came, Calhoun very wryly considered the situation. He couldn't know the actual state of things, to be sure. He'd been shot at. But even so--though that fact did not allow his hopes to be realized in every detail--the probability of a considerable success remained. It was not likely that the invaders would ascribe the finding of unconscious, stertoriously breathing members of their number to Calhoun. Making men unconscious was not the kind of warfare a plague-refugee would use. Still more certainly, it was not what the invaders themselves would practice. To devise and spread a plague, of course, was not beyond them. That had been done. But they would not disable an enemy and leave him alive. They would murder him or nothing. So when men of their group were found in something singularly close to the terminal coma of the plague, they'd think them victims. They'd guess that their supposed immunity was only to the early symptoms, not to the final ones and death. It should not be an encouraging opinion. But this morning Calhoun found himself hungry. He looked remorsefully at Murgatroyd. "I gave our rations to those refugees," he said regretfully. "I took no thought for the morrow--which has turned out to be today. I'm sorry, Murgatroyd!" Murgatroyd said nothing. "Maybe," suggested Calhoun, "we can find some of these invaders at a meal."