"Has he got the nerve?" Mr. Brodie demanded. "If we are on the right track, there's no room for weaklings in the job."

"Aaron Rodd's all right," his friend declared confidently. "You leave that to me. I'll answer for him."

The younger man leaned across the table.

"Do I understand," he enquired, "that our enterprise is on the side of the law?"

Harvey Grimm smiled.

"The present one, my dear Aaron. I should explain to you, perhaps, that Mr. Brodie is not officially attached either to Scotland Yard or to Police Headquarters in New York. He spent some years at Scotland Yard and, having the good luck to inherit a small fortune, and feeling himself handicapped by the antiquated methods and jealousies of his competitors, he decided to strike out for himself as an independent investigator. Some day he will tell us a few of his adventures."

Mr. Brodie had folded his arms and was looking very imposing.

"I have hunted criminals," he asserted, "in every quarter of the world. I have methods of my own. I have a genius for making use of people."

"So you see, my dear Aaron," Harvey Grimm pointed out, "at present Mr. Brodie and I are the greatest of friends. He recognises the fact that I am what is baldly spoken of as an adventurer, and that the time may come when we shall find ourselves in opposite camps, but just at present it is our privilege to be of service to Mr. Brodie."

Then a thing, ordinary enough in its way, happened in a curious manner. Mr. Brodie was a large man but he seemed suddenly to fade away. There was his empty chair and a dim vision of a retreating figure behind one of the central sideboards. Aaron Rodd seemed dimly conscious of a look of warning flashed between the two men, but nothing equal to the swift secrecy of Mr. Brodie's movements had ever confused his senses. Harvey Grimm leaned across the table, holding his liqueur glass in his hand.