“There was only one pipe,” replied Thorndyke, “and that was not his own.”

“Not his own!” exclaimed the captain, halting by a huge, chequered buoy to stare at my colleague. “How do you know it was not his own?”

“By the appearance of the vulcanite mouthpiece,” said Thorndyke. “It showed deep tooth-marks; in fact, it was nearly bitten through. Now a man who bites through his pipe usually presents certain definite physical peculiarities, among which is, necessarily, a fairly good set of teeth. But the dead man had not a tooth in his head.”

The captain cogitated a while, and then remarked: “I don’t quite see the bearing of this.”

“Don’t you?” said Thorndyke. “It seems to me highly suggestive. Here is a man who, when last seen, was filling his pipe with a particular kind of tobacco. He is picked up dead, and his pipe contains a totally different kind of tobacco. Where did that tobacco come from? The obvious suggestion is that he had met some one.”

“Yes, it does look like it,” agreed the captain.

“Then,” continued Thorndyke, “there is the fact that his sheath-knife is missing. That may mean nothing, but we have to bear it in mind. And there is another curious circumstance: there is a wound on the back of the head caused by a heavy bump against some body that was covered with acorn barnacles and marine worms. Now there are no piers or stages out in the open estuary. The question is, what could he have struck?”

“Oh, there is nothing in that,” said the captain. “When a body has been washing about in a tide-way for close on three days——”

“But this is not a question of a body,” Thorndyke interrupted. “The wound was made during life.”

“The deuce it was!” exclaimed the captain. “Well, all I can suggest is that he must have fouled one of the beacons in the fog, stove in his boat and bumped his head, though, I must admit, that’s rather a lame explanation.” He stood for a minute gazing at his toes with a cogitative frown and then looked up at Thorndyke.