"Well," McGill said, "nothing you've told me is impossible or supernatural. Just very, very improbable. In fact, the odds against that poker game alone would lead me to suspect Nat, well as I know him. It's all those other things...."
He got up and walked over to the window and looked at the hot twilight while I waited. Then he turned around; he had a look of concern.
"Alec, you're a reasonable guy, so I don't think you'll take offense at what I'm going to say. What you have told me is so impossibly unlikely, and the odds against it so astronomical, that I must take the view that you're either stringing me or you're subject to a delusion." I started to get up and expostulate, but he motioned me back. "I know, but don't you see that that is far more likely than...." He stopped and shook his head. Then he brightened. "I have an idea. Maybe we can have a demonstration."
He thought for a tense minute and snapped his fingers. "Have you any change on you?"
"Why, yes," I said. "Quite a bit." I reached into my pocket. There must have been nearly two dollars in silver and pennies. "Do you think they'll each have the same date, perhaps?"
"Did you accumulate all that change today?"
"No. During the week."
He shook his head. "In that case, no. Discounting the fact that you could have prearranged it, if my dim provisional theory is right, that would be actually impossible. It would involve time-reversal. I'll tell you about it later. No, just throw down the change. Let's see if they all come up heads."
I moved away from the carpet and tossed the handful of coins onto the floor. They clattered and bounced—and bounced together—and stacked themselves into a neat pile.