“How can I prove it?” cried Rufus Dawes, roughly impatient. “There are crimes committed which are never brought to light, and this is one of them.”

“Well,” said Rex, rising, as if weary of the discussion, “have it your own way, then. You know best. The private detective game is hard work. I, myself, have gone on a wild-goose chase before now. There's a mystery about a certain ship-builder's son which took me four months to unravel, and then I lost the thread.”

“A ship-builder's son! Who was he?”

John Rex paused in wonderment at the eager interest with which the question was put, and then hastened to take advantage of this new opening for conversation. “A queer story. A well-known character in my time—Sir Richard Devine. A miserly old curmudgeon, with a scapegrace son.”

Rufus Dawes bit his lips to avoid showing his emotion. This was the second time that the name of his dead father had been spoken in his hearing. “I think I remember something of him,” he said, with a voice that sounded strangely calm in his own ears.

“A curious story,” said Rex, plunging into past memories. “Amongst other matters, I dabbled a little in the Private Inquiry line of business, and the old man came to me. He had a son who had gone abroad—a wild young dog, by all accounts—and he wanted particulars of him.”

“Did you get them?”

“To a certain extent. I hunted him through Paris into Brussels, from Brussels to Antwerp, from Antwerp back to Paris. I lost him there. A miserable end to a long and expensive search. I got nothing but a portmanteau with a lot of letters from his mother. I sent the particulars to the ship-builder, and by all accounts the news killed him, for he died not long after.”

“And the son?”

“Came to the queerest end of all. The old man had left him his fortune—a large one, I believe—but he'd left Europe, it seems, for India, and was lost in the Hydaspes. Frere was his cousin.”