snapped around to face her in sudden fright. She was young and slim and slight, but she could scream loud enough to get help. Judging by the way she was looking at me, outwardly polite and yet visibly nervous, that scream would be coming at any second.

"I must have wandered in here by mistake," I said, and pushed past her to the corridor, where I began running back the way I had come.

"But you don't understand!" she cried after me. "I really want to help—"

Yeah, help, I thought, pounding toward the street door. A gag right out of that psychology film, probably—get the patient to hold still, humor him, until you can get somebody to put him where he belongs. That's what one of our teachers would do, provided she wasn't too scared to think straight, if she found an old-looking guy thumbing frenziedly through the textbooks in a grammar school classroom.

When I came to the outside door, I stopped. I had no way of knowing whether she'd given out an alarm, or how she might have done it, but the obvious place to find me would be out on the street, dodging for cover somewhere.

I pushed the door open and let it slam shut, hoping she'd hear it upstairs. Then I found a door, sneaked it open and went silently down the steps.

In the basement, I looked for a furnace or a coal bin or a fuel tank to hide behind, but there weren't any. I don't know how they got their heat in the winter or cooled the building in the summer. Probably some central atomic plant that took care of the whole city, piping in the heat or coolant in underground conduits that were led up through the walls, because there weren't even any pipes visible.

I hunched into the darkest corner I could find and hoped they wouldn't look for me there.