I could still read instruments. The pressure dial gave a direct depth of four thousand eight hundred eighty feet; a quick mental correction from the record tape of the thermograph added another two hundred or so. I certainly should be near the bottom, somewhere on the northern slopes of the mountain whose peaks are Rapanui.

I swung gently over the top and back down the other side, and my line of sight pointed downward again. Whether I wanted to believe my eyes or not, they insisted there was light in that direction. It was a gentle yellow-green glow — just the sort of thing you use in lighting effects to give the impression of an underwater scene. At first it looked uniform and smooth; then, a few turns later and two hundred feet lower, it showed a pattern. The pattern was of squares, with their corners just a little brighter than the rest of the area. It didn’t cover the whole bottom; its edge was almost below me, and it extended toward what I thought was the north, though my compass wasn’t reacting too well to the tumbling.

In the other direction was the normal comforting and frightening darkness — that was real enough.

Two things happened at almost the same instant. It became evident that I was going to come down pretty close to the edge of the light area, and it also became obvious what the light area was. The second realization got to me. For three or four seconds I was so furious and disgusted that I couldn’t plan, and as a result I almost didn’t get around to telling this story.

The light was artificial. Believe it if you can.

I realize that for a normal person it’s hard. Wasting watts to light up the outdoors is bad enough, but sometimes it’s a sad necessity. Spending power to illuminate the sea bottom, though — well, as I say, for a few moments I was too furious to think straight.