I put the phone back in its cradle carefully, like a rare and valuable egg. I tried to think. I'd been charging full speed ahead ever since I had decided on my scheme of action while I was still riding the surf off the Florida coast, and I'd stuck to it. Now it had hatched in my face--and the thing that had crawled out wasn't the downy little chick of success. It had teeth and claws and was eyeing me like a basilisk.... But I still had unplayed aces--if there was time. I had meant to use the matter transmitter to stage a dramatic proof that I wasn't the tool of the enemy. The demonstration would be more dramatic than I'd planned. The bomb would fit the machine as easily as the tape. The wheels would be surprised when their firecracker went off--right on schedule--in the middle of the Mojave Desert. I set to work, my heart pounding. If I could bring this off--if I had time--if the transmitter worked as advertised.... The stolen knowledge flowed smoothly, effortlessly. It was as though I had been assembling matter transmitters for years, knew every step by heart. First the moebius windings; yard after yard of heavy copper around a core of carbon; then the power supply, the first and second stage amplimitters.... How long? In the sump in the next room, the bomb lay quietly ticking. How long...? * * * * * The main assembly was ready now. I laid out cables, tying my apparatus in to the atomic power-source buried under the vault. The demand, for one short instant, would tax even those mighty engines. I fixed hooks at the proper points in the room, wove soft aluminum wire in the correct pattern. I was almost finished now. How long? I made the last connections, cleared away the litter. The matter transmitter stood on the table, complete. At any instant, the bomb would reduce it--and the secret of its construction--to incandescent gas--unless I transmitted the bomb out of range first. I turned toward the laundry room--and the telephone rang. I hesitated, then crossed the room and snatched it up. "Listen to me," Kayle said grimly. "Give me straight, fast answers. You said the Master Tape was there, in the vault with you. Now tell me: What does it look like?" "What?" "The ... ah ... dummy tape. What is its appearance?" "It's a roughly square plastic container, bright yellow, about a foot thick. What about it?" Kayle's voice sounded strained. "I've made inquiries. No one here seems to know the exact present location of the Master Tape. Each department says that they were under the impression that another handled the matter. I'm unable to learn who, precisely, removed the Tape from the vault. Now you say there is a yellow plastic container--" "I know what the Master Tape looks like," I said. "This is either it or a hell of a good copy."