"I don't know your name," he said, "but I have a very important post-operative case at present, and you keep charging around the ward when you're asleep. I just came over, as soon as I could get a few hours' sleep myself, to ask you to stop doing it, if you don't mind."
"I've done no such thing."
"You were doing it all last night, my friend."
"I was not," I said. "I spent last night here in my own bed. I didn't even dream."
"Ah, that probably accounts for it. Tell me, do you take drugs, tranquilizers, by any chance? We've had a lot of trouble with that. They seem to cause a bubble in the sequence of probabilities and things shift about. I've been taking a new one myself, while this case is on. I suspect that although I'm dreaming you, I think, you are not asleep at all. At least I wasn't when you made all that noise in my ward last night."
"No, I'm awake," I said. "Very much so."
"I see. Well, I shall wake up soon myself and go back to my own world, of course. But while I'm here, I suppose you haven't any advanced works on post-operative hyperspace relapse?
"Pity," he said, as I shook my head.
"I suppose you have no information on the fourth octave of ultra-uranium elements?"
He shook his head. "Didn't even know they existed," he said. "I don't believe they do in my probable time. What are you, a physicist? Ah," he added, as I nodded, "I wanted to specialize in physics when I was in college, but I went in for medicine instead."