"You won't get anywhere that way," Felder said wearily. "None of the data you give him verbally is used in his final computations, since it doesn't come from Daniel Oak, by his own reasoning." "That is correct, sir," said McGuire. "Idiot machine!" said Vivian Deveraux angrily. I shut up and did some more thinking. Talking only made my throat hurt. Nobody could argue impressively with McGuire except Daniel Oak, and as far as McGuire was concerned Mr. Oak was keeping an impressive silence. "Maybe I could write out the orders," I said. "Nope," said Videnski. "He can read, but information coming in that way isn't counted as orders, not even from you. We should have installed a teletyper, too, but this is a little late for thinking of that." "McGuire," I whispered, "what sort of proof would be needed to show you that this is the voice of Daniel Oak?" "I'm sorry, sir," McGuire said after a moment, "but that information is not in my banks." "Maybe somebody could imitate Dan's voice," Vivian said hopefully. Videnski and Felder shook their heads in unison. "No dice," Videnski said rumblingly. "It not only has to sound like Oak, it has to come from Oak." "Ventriloquism?" Vivian said with a half-hearted grin. "Wouldn't fool McGuire for an instant," Felder said. "That's an audio-visual trick of the human mind, not of a robot's." The ship kept on moving. McGuire went serenely on, following his last orders. We finally reached the point where we were too tired to think, and sleep became imperative. We were nearly two days out of Ceres. When I announced my intention of taking a snooze, Felder looked at me through groggy, bloodshot eyes. "Hadn't we better sleep in two shifts? I mean, just in case there's another spy among us?" I shook my head. "No spy would try anything now. There isn't anything to try. We're all safe, as far as that's concerned. I'll go in and sleep in my assigned room. Not even Brentwood could or would do anything to me now." "For that matter," Felder said, "it's senseless to keep him locked up now. He's harmless until we reestablish control over McGuire. When that happens, we can lock him up again." "My sentiments exactly," I said in my new hoarse, breathy, susurrant voice. Brentwood didn't say much when I gave him the news; he just thanked me. I got into bed and worried for a while, but lack of sleep soon cut off my ability to worry. I only woke up once in the next nine hours, when McGuire changed course a trifle to avoid some unseen meteor. Not even the ache in my throat kept me from sleep. * * * * * It was Videnski's voice that woke me up. The door of my room was slid open a little, and I could hear him in the lounge. I got to my feet fast, shoved open the door, and went out.