It was the maid with a telegram. Holmes tore it open and burst out laughing.

“Well, well! What next?” said he. “Brother Mycroft is coming round.”

“Why not?” I asked.

“Why not? It is as if you met a tram-car coming down a country lane. Mycroft has his rails and he runs on them. His Pall Mall lodgings, the Diogenes Club, Whitehall—that is his cycle. Once, and only once, he has been here. What upheaval can possibly have derailed him?”

“Does he not explain?”

Holmes handed me his brother’s telegram.

“Must see you over Cadogan West. Coming at once.”
MYCROFT.

“Cadogan West? I have heard the name.”

“It recalls nothing to my mind. But that Mycroft should break out in this erratic fashion! A planet might as well leave its orbit. By the way, do you know what Mycroft is?”

I had some vague recollection of an explanation at the time of the Adventure of the Greek Interpreter.