"All unmounted—like this?" asked Chettle.
"All unmounted—like that," affirmed Allerdyke. "And now, then, since it seems to be a matter of importance, I can tell you what James did with at any rate two of 'em. He gave one to our cousin Grace—Mrs. Henry Mallins—a Bradford lady. He gave another to a friend of my own, another amateur photographer, Wilson Firth—gave him it in my presence at the Midland Hotel one day, when we were all three having a cigar together in the smoking-room there. Wilson Firth's a bit of a rival of mine in the amateur photographic line—we each try to beat the other, you understand. Now, then, James pulled one of these snapshots out and handed it over to Wilson with a laugh. 'There,' he says, 'that's our Marshall's latest performance—you'll have a job to do aught better than that, Wilson, my lad,' he says. So that accounts for two. And—this is the third!"
"And the question, Mr. Allerdyke, the big question—a most important question!—is, how did it come into this man Lydenberg's possession?" said the detective anxiously. "If we can find that out—"
"I've been thinking," interrupted Allerdyke. "There's this about it, you know: James and this Lydenberg came over together from Christiania to Hull in the Perisco. They talked to one another—that's certain. James may have given it to Lydenberg. But the thing is—is that likely?"
"No!" replied Chettle, with emphatic assurance. "No, sir! And I'll tell you why. If your cousin had given this photo to Lydenberg, as he might, of course, have given it to a mere passing acquaintance, because that acquaintance took a fancy to it, or something of that sort, Lydenberg would in all reasonable probability have just slipped in into his pocket-book, or put it loose amongst his letters and papers. But, as we see, however Lydenberg became possessed of this photo, he took unusual pains and precautions about it. You see, he cut it down, most carefully and neatly, to fit into the cover of his watch—he took the trouble to carry it where no one else would see it, but where he could see it himself at a second's notice—he'd nothing to do but to snap open that cover. No, sir, your cousin didn't give that photo to Lydenberg. That photo was sent to Lydenberg, Mr. Allerdyke—sent! And it was sent for one purpose only. What? That he should be able to identify Mr. James Allerdyke as soon as he set eyes on him!"
Allerdyke nodded his head—in complete understanding and affirmation. He was thinking the same thing—thinking, too, that here was at least a clue, a real tangible clue.
"Aye!" he said. "I agree with you. Then, of course, the one and only thing to do is—"
"To find out who the person was that your cousin gave this particular print to!" said Chettle eagerly. "Of course, it's a big field. So far as I understand things, he'd been knocking round a good bit between the time of your taking this photo and his death. He'd been in London, hadn't he? And in Russia—in two or three places. How can we find out when and how he parted with this? For give it to somebody he did, and that somebody was a person who knew of the jewel transaction, and employed Lydenberg in it, and sent the photo to Lydenberg so that he should know your cousin by sight—at once. Mr. Allerdyke, the secret of these murders and thefts is—there!"
Chettle replaced the watch in the cardboard box from which he had taken it, produced a bit of sealing-wax from his pocket, sealed up the box, and put it and the other things belonging to Lydenberg back in the small trunk from which he had withdrawn them to show his companion. And Allerdyke watched him in silence, wondering and speculating about this new development.
"What do you want me to do?" he asked suddenly. "You've got some scheme, of course, or you wouldn't have got me down here alone."