"Much obliged to you for coming so promptly, Mr. Allerdyke," said the detective. "And for coming by yourself—that was just what I wanted."

"Aye, and why?" asked Allerdyke. "Why by myself? I've been wondering about that all the way down."

Chettle, a sleek, comfortable-looking man, with a quiet manner and a sly glance, laughed knowingly, twiddling his fat thumbs as he leaned back in the cab. "Oh, well, it doesn't do—in my opinion—to spread information amongst too many people, Mr. Allerdyke," he said. "That's my notion of things, anyway. I just wanted to go into a few matters with you, alone, d'ye see? I didn't want that American gentleman along with you. Eh?"

"Now, why?" asked Allerdyke. "Out with it!"

"Well, you see, Mr. Allerdyke," answered the detective, "we know you. You're a man of substance, you've got a big stake in the country—you're Allerdyke, of Allerdyke and Partners, Limited, Bradford and London. But we don't know Fullaway. He may be all right, but you could only call him a bird of passage, like. He can close down his business and be away out of England to-morrow, and, personally, I don't believe in letting him into every secret about all this affair until we know more about him. You see, Mr. Allerdyke, there's one thing very certain—so far as we've ascertained at present, nobody but Fullaway, and possibly whoever's in his employ, was acquainted with the fact that your cousin was carrying those jewels from Russia to England. Nobody in this country, at any rate. And—it's a thing of serious importance, sir."

Just what Appleyard had said!—what, indeed, no one of discernment could help saying, thought Allerdyke. The sole knowledge, of course, was with Fullaway and his lady clerk—so far as was known. Therefore—

"Just so," he said aloud. "I see your point—of course, I've already seen it. Well, what are we going to do—now? You've brought me down here for something special, no doubt."

"Quite so, sir," answered Chettle composedly. "I want to draw your attention to some very special features and to ask you certain questions arising out of 'em. We'll take things in order, Mr. Allerdyke. We're driving now to the High Street—I want to show you the exact spot where Lydenberg was shot dead. After that we'll go to the police-station and I'll show you two or three little matters, and we'll have a talk about them. And now, before we get to the High Street, I may as well tell you that on examining Lydenberg's body very little was found in the way of papers—scarcely anything, and nothing connecting him with your cousin's affair—in fact, the police here say they never saw a foreign gentleman with less on him in that way. But in the inside pocket of his overcoat there was a postcard, which had been posted here in Hull. Here it is—and you'll see that it was the cause of taking him to the spot where he was shot."

Chettle took from an old letter-case an innocent-looking postcard, on one corner of which was a stain.

"His blood," he remarked laconically. "He was shot clean through the heart. Well, you see, it's a mere line."