“I wish you’d lend me this for a day or two,” he said at last.  “I’ll take the greatest care of it; it shan’t go out of my own personal possession, and I’ll return it by registered post.  The fact is, Mr. Smeaton, I want to compare that writing with some other writing.”

“Certainly,” agreed Smeaton, handing the letter over.  “I’ll do anything I can to help.  I’m beginning, you know, Mr. Lindsey, to fear I’m mixed up in this.  You’ll keep me informed?”

“I can give you some information now,” answered Mr. Lindsey, pulling out the telegram.  “There’s more mystery, do you see?  And Moneylaws and I are off to Largo now—­we’ll take it on our way home.  For by this and that, I’m going to know what’s become of Sir Gilbert Carstairs!”

We presently left Mr. Gavin Smeaton, with a promise to keep him posted up, and a promise on his part that he’d come to Berwick, if that seemed necessary; and then we set out on our journey.  It was not such an easy business to get quickly to Largo, and the afternoon was wearing well into evening when we reached it, and found the police official who had wired to Berwick.  There was not much that he could tell us, of his own knowledge.  The yacht, he said, was now lying in the harbour at Lower Largo, where it had been brought in by a fisherman named Andrew Robertson, to whom he offered to take us.  Him we found at a little inn, near the harbour—­a taciturn, somewhat sour-faced fellow who showed no great desire to talk, and would probably have given us scant information if we had not been accompanied by the police official, though he brightened up when Mr. Lindsey hinted at the possibility of reward.

“When did you come across this yacht?” asked Mr. Lindsey.

“Between eight and nine o’clock this morning,” replied Robertson.

“And where?”

“About seven miles out—­a bit outside the bay.”

“Empty?” demanded Mr. Lindsey, looking keenly at the man.  “Not a soul in her?”

“Not a soul!” answered Robertson.  “Neither alive nor dead!”

“Were her sails set at all?” asked Mr. Lindsey.

“They were not.  She was just drifting—­anywhere,” replied the man.  “And I put a line to her and brought her in.”

“Any other craft than yours about at the time?” inquired Mr. Lindsey.

“Not within a few miles,” said Robertson.

We went off to the yacht then.  She had been towed into a quiet corner of the harbour, and an old fellow who was keeping guard over her assured us that nobody but the police had been aboard her since Robertson brought her in.  We, of course, went aboard, Mr. Lindsey, after being assured by me that this really was Sir Gilbert Carstairs’ yacht, remarking that he didn’t know we could do much good by doing so.  But I speedily made a discovery of singular and significant importance.  Small as she was, the yacht possessed a cabin—­there was no great amount of head-room in it, it’s true, and a tall man could not stand upright in it, but it was spacious for a craft of that size, and amply furnished with shelving and lockers.  And on these lockers lay the clothes—­a Norfolk suit of grey tweed—­in which Sir Gilbert Carstairs had set out with me from Berwick.