“I was going down to Birlstone this morning,” said he. “I had come to ask you if you cared to come with me—you and your friend here. But from what you say we might perhaps be doing 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 Birlstone mystery in a day or two; but where’s the mystery if there is a man in London who prophesied 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 in Camberwell—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?”
“In notes to Camberwell post office.”
“Did you ever trouble to see who called for them?”
“No.”
The inspector looked surprised and a little shocked. “Why not?”
“Because I always keep faith. I had promised when he first wrote that I would not try to trace him.”
“You think there is someone behind him?”
“I know there is.”
“This professor that I’ve heard you mention?”
“Exactly!”
Inspector MacDonald smiled, and his eyelid quivered as he glanced towards me. “I won’t conceal from you, Mr. Holmes, that we think in the C.I.D. that you have a wee bit of a bee in your bonnet over this professor. I made some inquiries myself about the matter. He seems to be a very respectable, learned, and talented sort of man.”