The door had not yet closed and I slipped in, with my heart irretrievably contracted to the size of a buckshot. I could just make out in the dim light that I was at the bottom of the fire stairs, so I climbed to the third floor and went into a classroom, then on into an office somewhat like McGill's, that faced toward the lab building.
From here, I had a perfect view of the crowd, the police, the upper facade of the labs, brightly lit by the searchlight and, over all, the spinning papers and dust, which even as I looked began to die down. I was unable to see Molly or McGill and wondered whether they had noticed my absence and were worrying.
I saw a phone on the desk at my side and considered calling up McGill's office, but first I wanted to think over my new idea. I pulled down the shades and turned on the reading lamp, by the light of which I re-examined the fragment I had been carrying around all day. It sparkled brilliantly. On the desk, beside an onyx pen-set, a golf trophy and a signed golf ball, was a leather-framed photograph of a blank-faced young woman holding a pudgy little boy. I picked it up and rubbed the glass with the tiny fragment. It left a faint but undeniable scratch. So I was right about one thing.
Then I called McGill's office. In a few moments, I heard the receiver lifted, but no voice. "This is the nucleus," I said, and I heard of sigh of relief from McGill.
"Where in hell are you?"
"Across the way. Look, out of your window and I'll turn my light off and on again." I did so.
"You're in Professor Crandal's office. Why did you leave?"
"We'll go into that later. McGill, that fragment is a diamond."
"What!"
"At any rate, it scratches glass."