What kind of a test would it be? He wondered. And how fair? Nogol came trotting up lightly. "Ryan, I found some more wart-hogs and they keeled over as soon as they saw me." "So it _was_ xenophobia," Ekstrohm ventured. "The important thing," Ryan said, with a sidelong glance at the surveyor, "is that now we've got what it takes to see if Ekstrohm has been deliberately sabotaging this expedition." * * * * * The body heat of the three men caused the air-conditioner of the tiny bubble to labor. "Okay," Ryan breathed. "We've got our eyes on you, Ekstrohm, and the video circuits are wide open on the dead beasts. All we have to do is wait." "We'll have a long wait," Nogol ventured. "With Ekstrohm here, and the corpses out there, nothing is going to happen." That would be all the proof they needed, Ekstrohm knew. Negative results would be positive proof to them. His pink ticket would turn pure red and he would be grounded for life--_if_ he got off without a rehabilitation sentence. But if nothing happened, it wouldn't really prove anything. There was no way to say that the conditions tonight were identical to the conditions the previous night. What had swept away those bodies might be comparable to a flash flood. Something that occurred once a year, or once in a century. And perhaps his presence outside _was_ required in some subtle cause-and-effect relationship. All this test would prove, if the bodies didn't disappear, was only that conditions were not identical to conditions under which they did disappear. Ryan and Nogol were prepared to accept him, Ekstrohm, as the missing element, the one ingredient needed to vanish the corpses. But it could very well be something else. Only Ekstrohm knew that it _had_ to be something else that caused the disappearances. _Or did it?_ He faced up to the question. How did he know he was sane? How could he be sure that he hadn't stolen and hid the bodies for some murky reason of his own? There was a large question as to how long a man could go without sleep, dreams and oblivion, and remain sane. Ekstrohm forced his mind to consider the possibility. Could he remember every step he had taken the night before? It seemed to him that he could remember walking past the creature lying in the grass, then walking in a circle, and coming back to the base. It seemed like that to him. But how could he know that it was true? He couldn't. * * * * * There was no way he could prove, even to himself, that he had not disposed of those alien remains and then come back to his bubble, contented and happy at the thought of fooling those smug idiots who could sleep at night. "How much longer do we have to wait?" Nogol asked. "We've been here nine hours. Half a day. The bodies are right where I left them outside. There doesn't seem to be any more question."