a list of them. It means a devil of a lot of concentration for the ordinary person, if he wants to get his list complete, but in some odd way I manage to do it without concentration at all. I mean that my eyes seem to do it without the brain consciously taking any part. I could look at the tray, for instance, and talk to you about golf at the same time, and still get my list right."
"I should think that's rather a useful gift for an amateur detective. You ought to have gone into the profession before."
"Well, it is rather useful. It's rather surprising, you know, to a stranger. Let's surprise Cayley with it, shall we?"
"How?"
"Well, let's ask him" Antony stopped and looked at Bill comically, "let's ask him what he's going to do with the key of the office."
For a moment Bill did not understand.
"Key of the office?" he said vaguely. "You don't mean—Tony! What do you mean? Good God! do you mean that Cayley—But what about Mark?"
"I don't know where Mark is—that's another thing I want to know—but I'm quite certain that he hasn't got the key of the office with him. Because Cayley's got it."
"Are you sure?"
"Quite."
Bill looked at him wonderingly.
"I say," he said, almost pleadingly, "don't tell me
