"Not going to blindfold me, Lieutenant?" I asked.

"No need." He grinned. "If you're on the up and up, it's not necessary. if you're not on the up and up, it's still not necessary, for you can't talk about what you've seen — not to anyone that matters — if you're going to -spend the next few years staring out from behind a set of prison bars."

I saw his point. I followed him for'ard, our feet soundless on the black rubber decking, past the tops of a couple of huge machines readily identifiable as turbo-generator sets for producing electricity. More heavy banks of instruments, a door, then a thirty-foot-long very narrow passageway. As we passed along its length I was conscious of a heavy vibrating hum from beneath my feet. The «Dolphin's» nuclear reactor had to be somewhere. This would be it, here. Directly beneath us. There were circular hatches on the passageway deck and those could only be covers for the heavily leaded glass windows, inspection ports that would provide the nearest and only approach to the nuclear furnace far below.

The end of the passage, another heavily clamped door, and then we were into what was obviously the control center of the «Dolphin». To the left was a partitioned-off radio room, to the right a battery of machines and dialed panels of incomprehensible purpose, and straight ahead, a big chart table. Beyond that again, in the center, were massive mast housings and, still further on, the periscope stand with its twin periscopes. The whole control room was twice the size of any I'd ever seen in a conventional submarine but, even so, every square inch of bulkhead space seemed to be taken up by one type or another of highly complicated looking machines or instrument banks: even the deckhead was almost invisible, lost to sight above thickly twisted festoons of wires, cables and pipes of a score of different kinds.