It was one of those dramatic moments for which my friend existed. It would be anoverstatement to say that he was shocked or even excited by the amazing announcement.Without having a tinge of cruelty in his singular composition, he was undoubtedly callousfrom long overstimulation. Yet, if his emotions were dulled, his intellectual perceptionswere exceedingly active. There was no trace then of the horror which I had myself felt atthis curt declaration; but his face showed rather the quiet and interested composure of thechemist who sees the crystals falling into position from his oversaturated solution."Remarkable!" said he. "Remarkable!""You don't seem surprised.""Interested, Mr. Mac, but hardly surprised. Why should I be surprised? I receive ananonymous communication from a quarter which I know to be important, warning me thatdanger threatens a certain person. Within an hour I learn that this danger has actuallymaterialized and that the person is dead. I am interested; but, as you observe, I am notsurprised."In a few short sentences he explained to the inspector the facts about the letter and thecipher. MacDonald sat with his chin on his hands and his great sandy eyebrows bunchedinto a yellow tangle."I was going down to Birlstone this morning," said he. "I had come to ask you if you caredto come with me-you and your friend here. But from what you say we might perhaps bedoing better work in London.""I rather think not," said Holmes."Hang it all, Mr. Holmes!" cried the inspector. "The papers will be full of the Birlstonemystery in a day or two; but where's the mystery if there is a man in London whoprophesied the crime before ever it occurred? We have only to lay our hands on that man, and the rest will follow.""No doubt, Mr. Mac. But how do you propose to lay your hands on the so-called Porlock?"MacDonald turned over the letter which Holmes had handed him. "Posted inCamberwell-that doesn't help us much. Name, you say, is assumed. Not much to go on, certainly. Didn't you say that you have sent him money?""Twice.""And how?"