“Good afternoon, Inspector,” he said.  “I’m really sorry I had to interrupt you as I did; but I most awfully wanted you to know that you owe me a Homburg hat.”  He went closer to the detective.  “You see, I have won that wager.  I have found the man who murdered Captain Fraser-Freer.”

Curiously enough, Bray said nothing.  He sat down at his desk and idly glanced through the pile of mail that lay upon it.  Finally he looked up and said in a weary tone: 

“You’re very clever, I’m sure, Colonel Hughes.”

“Oh—­I wouldn’t say that,” replied Hughes.  “Luck was with me —­from the first.  I am really very glad to have been of service in the matter, for I am convinced that if I had not taken part in the search it would have gone hard with some innocent man.”

Bray’s big pudgy hands still played idly with the mail on his desk.  Hughes went on:  “Perhaps, as a clever detective, you will be interested in the series of events which enabled me to win that Homburg hat?  You have heard, no doubt, that the man I have caught is Von der Herts—­ten years ago the best secret-service man in the employ of the Berlin government, but for the past few years mysteriously missing from our line of vision.  We’ve been wondering about him—­at the War Office.”

The colonel dropped into a chair, facing Bray.

“You know Von der Herts, of course?” he remarked casually.

“Of course,” said Bray, still in that dead tired voice.

“He is the head of that crowd in England,” went on Hughes.  “Rather a feather in my cap to get him—­but I mustn’t boast.  Poor Fraser-Freer would have got him if I hadn’t—­only Von der Herts had the luck to get the captain first.”

Bray raised his eyes.

“You said you were going to tell me—­” he began.

“And so I am,” said Hughes.  “Captain Fraser-Freer got in rather a mess in India and failed of promotion.  It was suspected that he was discontented, soured on the Service; and the Countess Sophie de Graf was set to beguile him with her charms, to kill his loyalty and win him over to her crowd.

“It was thought she had succeeded—­the Wilhelmstrasse thought so—­we at the War Office thought so, as long as he stayed in India.

“But when the captain and the woman came on to London we discovered that we had done him a great injustice.  He let us know, when the first chance offered, that he was trying to redeem himself, to round up a dangerous band of spies by pretending to be one of them.  He said that it was his mission in London to meet Von der Herts, the greatest of them all; and that, once he had located this man, we would hear from him again.  In the weeks that followed I continued to keep a watch on the countess; and I kept track of the captain, too, in a general way, for I’m ashamed to say I was not quite sure of him.”