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 Cadogen West. Coming at once.

Mycroft.

"Cadogen 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.

"You told me that he had some small office under the British government."

Holmes chuckled.

"I did not know you quite so well in those days. One has to be discreet when one talks of high matters of state. You are right in thinking that he under the British government. You would also be right in a sense if you said that occasionally he IS the British government."