"I would have to explain," said McCauley grimly, "that Lieutenants Kent and Holmes intended to murder each other, and each one threw away an air tank he expected the other man to use--but he expected to have plenty of air for himself! I would have to explain that Farside was isolated because two would-be murderers had outsmarted themselves and didn't have the guts to face the consequences!" Kent's voice came from a speaker. He spoke from that distant mountain peak toward which darkness crept steadily. "Look here, sir." His tone was defiant. "If that sledge is brought back," said McCauley angrily, "I'll court-martial whoever comes back with it, even the two of you! If one of you comes back, there'll be a court of inquiry. Maybe you've worked out a pretty story of an accident for the survivor to tell. But you can't use it now, because I found the air tanks you threw away! If one of you comes back, the inquiry will end in a court-martial and a murder verdict!" Holmes' voice, stiff and steady, was as defiant as Kent's had been. "I take it, sir, that you're advising neither of us to come back. Very well, sir! We've a little matter to settle between us. We can settle that and the one who's left...." "If neither of you comes back," rasped McCauley, "the inquiry into your deaths will inform an interested world that two officers--and supposedly gentlemen--of the Space Service were actually two smart, snide, shabby killers who overreached themselves! The Service will be proud to have it known that its officers try to murder each other by throwing away each other's air tanks. The Service will be very, very proud!" The irony of the last words was corrosive. "Sir...." The two voices spoke together, outraged and despairing. "Sir," panted Kent's voice, alone. "We'd no idea of anything like that, sir! We've always hated each other, but...." His voice ended in a gulp. McCauley growled. A young officer can be very much of a fool, of course, but he can be desperately solicitous for the honor of the Service to which he is attached. McCauley spoke with icy precision. "I am not concerned with your lives or your hatreds or your intentions. I am concerned with the good name of the Space Service. I order you both to come back here. Alive. Together. You will start immediately!" A dazed silence. Then Kent said: "But--you don't want us to bring the sledge...." "And we haven't--" this was Holmes--"we haven't enough air to get back! How can we do it, sir?" McCauley relaxed in his small cubbyhole of an office. Very privately he drew a breath of relief. But his tone remained stern. "You will head for Repeater One. If you remember, my voice goes from the base here to Repeater One where it is relayed to Repeater Two. If I chose the proper frequency it would go on through Three and Four to Farside. Can you think of any advantage in being at Repeater One instead of Two?" A long pause. Then Holmes' voice, dubious: