"See that balcony. Let me off there."

The driver stared back at me, wide-eyed. "We aren't allowed to do that, mister."

"I realize that," I said, handing him a twenty credit note. "But I want to play a joke on a friend."

"All right, buddy," he said, maneuvering his copter closer to the building. "Remember, if you land on the pavement below, I don't offer any guarantees."

He hovered stationary beside my balcony and I leaped across the air space of two or three feet and slipped and clung, and finally scrambled to safety.

I could see into my darkened office. It didn't look as if anyone was there. Then a new problem presented itself. How to open the unbreakable strontium-alloy window? There was no way at all to do it from the outside.

Why hadn't I thought of that!

I looked down sixty-eight stories, and looked up forty-one stories, and realized I was trapped.

Unless I could reach the balcony outside Charlie's office. Oh my God, I thought—a human fly act! That was ten feet away, and I am six-foot-one tall. Moreover, the wind was blowing in the wrong direction. And the face of the building was perfectly smooth. Not a thing to use as a hand-hold.

There was another possibility. I took off one of my shoes and hurled it at Charlie's window. It missed, but fortunately remained on the balcony. I took off the other one. It struck his window with a dull clonk.