Allerdyke went off to Hull, post-haste, because of a telephone call which roused him out of bed an hour before his usual time. It came from Chettle, the New Scotland Yard man who had been sent down to Hull as soon as the news of Lydenberg's murder arrived. Chettle asked Allerdyke to join him by the very next express, and to come alone; he asked him, moreover, not to tell Mr. Franklin Fullaway whither he was bound. And Allerdyke, having taken a quick glance at a time-table, summoned Gaffney, told him of his journey, bade him keep his tongue quiet at the Waldorf, wrote his hasty note to Appleyard, dressed, and hurried away to King's Cross. He breakfasted on the train, and was in Hull by one o'clock, and Chettle hailed him as he set foot on the platform, and immediately led him off to a cab which awaited them outside the station.

"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."

Allerdyke took the card and looked at it with a mingled feeling of repulsion and fascination. The writing on it was thin, angular, upright, and it suggested foreign origin. And the communication was brief—and unsigned—

"High Street morning eleven sharp left-hand side old houses."

"You don't recognize that handwriting, of course, Mr. Allerdyke?" asked Chettle. "Never seen it before, I suppose?"

"No!" replied Allerdyke. "Never. But I should say it's a foreigner's."

"Very likely," assented Chettle. "Aye, well, sir, it lured the man to his death. And now I'll show you where he died, and how easy it was for the murderer to kill him and get away unobserved."

He pulled the cab up at the corner of the High Street, and turned southward towards the river, looking round at his companion with one of his sly smiles.

"I daresay that you, being a Yorkshireman, Mr. Allerdyke, know all about this old street," he remarked as they walked forward. "I never saw it, never heard of it, until the other day, when I was sent down on this Lydenberg business, but it struck me at once. I should think it's one of the oldest streets left in England."

"It is," answered Allerdyke. "I know it well enough, and I've seen it changed. It used to be the street of the old Hull merchants—they had their houses and warehouses all combined, with gardens at the back running down to the river Hull. Queer old places there used to be in this street, I can tell you when I was a lad!—of late years they've pulled a lot of property down that had got what you might call thoroughly worm-eaten—oh, yes, the place isn't half as ancient or picturesque as it was even twenty years ago!"

"There's plenty of the ancient about it still, for all that," observed Chettle, with a dry laugh. "There was more than enough of it for Lydenberg the other day, at any rate. Now, then, you remember what it said on the postcard—he was to walk down the High Street, on the left-hand side, at eleven o'clock? Very well—down the High Street he walks, on this side which we are now—he strolls along, by these old houses, looking about him, of course, for the person he was to meet. The few people who were about down here that morning, and who saw him, said that he was looking about from side to side. And all of a sudden a shot rang out, and Lydenberg fell—just here—right on this very pavement."

He pulled Allerdyke up in a narrow part of the old street, jointed to the flags, and then to the house behind them—an ancient, ramshackle place, the doors and windows of which were boarded up, the entire fabric of which showed unmistakable readiness for the pick and shovel of the house-breaker. And he laid a hand on one of the shattered windows, close by a big hole in the decaying wood.

"There's no doubt the murderer was hidden behind this shutter, and that he fired at Lydenberg from it, through this hole," he said. "So, you see, he'd only be a few feet from his man. He was evidently a good shot, and a fellow of resolute nerve, for he made no mistake. He only fired once, but he shot Lydenberg clean through the heart, dead!"

"Anybody see it happen?" asked Allerdyke, staring about him at the scene of the tragedy, and thinking how very ordinary and commonplace everything looked. "I suppose there'd be people about, though the street, at this end, anyway, isn't as busy as it once was?"

"Several people saw him fall," answered Chettle.

"They say he jumped, spun round, and fell across the pavement. And they all thought it was a case of suicide. That, of course, gave the murderer a bigger and better chance of making off. You see, as these people saw no assailant, it never struck 'em that the shot had been fired from behind this window. When they collected their thoughts, found it wasn't suicide, and realized that it was murder, the murderer was—Lord knows where! From behind these old houses, Mr. Allerdyke, there's a perfect rabbit-warren of alleys, courts, slums, twists, and turns! The man could slip out at the back, go left or right, mix himself up with the crowd on the quays and wharves, walk into the streets, go anywhere—all in a minute or two."

"Clever—very clever! You've no clue?" asked Allerdyke.

"None; not a scrap!" replied the detective. "Bless you, there's score of foreigners knocking about Hull. Scores! Hundreds! We've done all we can, the local police and myself—we've no clue whatever. But, of course, it was done by one of the gang."

"By one of the gang!" exclaimed Allerdyke. "Ah you've got a theory of your own, then?"

Chettle laughed quietly as they turned and retraced their steps up the street.

"It 'ud be queer if I hadn't, by this time," he answered. "Oh yes, I've thought things out pretty well, and I should say our people at the Yard have come to the same conclusion that I have—I'm not conceited enough, Mr. Allerdyke, to fancy that I'm the only person who's arrived at a reasonable theory, not I?"

"Well—what is your theory?" asked Allerdyke.

"This," replied the detective. "The whole thing, the theft of the Princess Nastirsevitch's jewels from your cousin, of Miss de Longarde's or Lennard's jewels, was the work of a peculiarly clever gang—though it may be of an individual—who made use of both Lydenberg and the French maid as instruments, and subsequently murdered those two in order to silence them forever. I say it may be the work of an individual—it's quite possible that the man who killed the Frenchwoman is also the man who shot Lydenberg—but it may be the work of one, two, or three separate persons, acting in collusion. I believe that Lydenberg was the actual thief of the Princess's jewels from your cousin; that the Frenchwoman actually stole her mistress's jewels. But as to how it was worked—as to who invented and carried out the whole thing—ah!"

"And to that—to the real secret of the whole matter—we haven't the ghost of a clue!" muttered Allerdyke. "That's about it, eh?"

Chettle laughed—a sly, suggestive laugh. He gave his companion one of his half-apologetic looks.

"I'm not so sure, Mr. Allerdyke," he said. "We may have—and that's why I wanted to see you by yourself. Come round to the police-station."

In a quiet room in the usual drab and dismal atmosphere which Allerdyke was beginning to associate with police affairs, Chettle produced the personal property of the dead man, all removed, he said, from the Station Hotel, for safe keeping.

"There's little to go on, Mr. Allerdyke," he said, pointing to one article after another. "You'll remember that the man represented himself as being a Norwegian doctor, who had come to Hull on private business. He may have been that—we're making inquiries about him in Christiania, where he hailed from. According to those who're in a position to speak, his clothing, linen, boots, and so on are all of the sort you'd get in that country. But he'd no papers on him to show his business, no private letters, no documents connecting him with Hull in any way: he hadn't even a visiting-card. He'd a return ticket—from Hull to Christiania—and he'd plenty of money, English and foreign. When I got down here, I helped the local police to go through everything—we even searched the linings of his clothing and ripped his one handbag to pieces. But we've found no more than I've said. However—I've found something. Nobody knows that I've found it. I haven't told the people here—I haven't even reported it to headquarters in London. I wanted you to see it before I spoke of it to a soul. Look here!"

Chettle opened a square cardboard box in which certain personal effects belonging to Lydenberg had been placed—one or two rings, a pocket-knife, his purse and its contents, a cigar-case, his watch and chain. He took up the watch, detached it from the chain, and held it towards Allerdyke, who was regarding these proceedings with intense curiosity.

"You see this watch, Mr. Allerdyke," he said. "It's a watch of foreign make—Swiss—and it's an old one, a good many years old, I should say. Consequently, it's a bit what we might call massive. Now, I was looking at it yesterday—late last night, in fact—and an idea suddenly struck me. In consequence of that idea, I opened the back of the watch, and discovered—that!"

He snapped open the case of the watch as he spoke and showed Allerdyke, neatly cut out to a circle, neatly fitted into the case, a photograph—the photograph of James Allerdyke! And Allerdyke started as if he had been shot, and let out a sharp exclamation.

"My God!" he cried. "James! James, by all that's holy—and in there!"

"You recognize it, of course?" said Chettle, with a grim smile. "No doubt of it, eh?"

"Doubt! Recognize!" exclaimed Allerdyke. "Lord, man—why, I took it myself, not two months ago!"

CHAPTER XVIII
DEFINITE SUSPICION

Chettle laughed—a low, suggestive, satisfied chuckle. He laid the watch, its case still open, on the table at which they were standing, and tapped the photograph with the point of his finger.

"That may be the first step to the scaffold—for somebody," he said, with a meaning glance. "Ah—it's extraordinary what little, innocent-looking things help to put a bit of rope round a man's neck! So you took this, Mr. Allerdyke?—took it yourself, you say?"

"Took it myself, some eight or nine weeks ago," answered Allerdyke. "I took it in my garden one Sunday afternoon when my cousin James happened to be there. I do a bit in that way—amusement, you know. I just chanced to have a camera in my hand, and I saw James in a very favourable light and position, and I snapped him. And it was such a good 'un when developed that I printed off a few copies."

The detective's face became anxious.

"How many, now?" he asked. "How many, Mr. Allerdyke? I hope you can remember?—it's a point of the utmost seriousness."

"Naught easier," answered Allerdyke readily. "I've a good memory for little things as well as big 'uns. I printed off four copies. One of 'em I pasted into an album in which I keep particularly good photographs of my own taking; the other three I gave to him—he put 'em in his pocket-book."

"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."

"Just so," agreed Chettle. "I have a scheme—and that's why I did get you down here alone. Mr. Allerdyke, you're a sharp, shrewd man—all you Yorkshiremen are!—at least, all that I've ever come across. You're good hands at ferreting things out. Now, Mr. Allerdyke, let's be plain—there's no two ways about it, no doubt whatever of it, the only people in England that we're aware of who knew about this Nastirsevitch jewel transaction are—Fullaway and whoever he has in his employ! We know of nobody else—unless, indeed, it's the Chicago millionaire, Delkin, and he's not very likely to have wanted to go in for a job of this sort. No, sir—Fullaway is the suspected person, in my opinion!—though I'm going to take precious good care to keep that opinion to myself yet awhile, I can tell you. Fullaway, Mr. Allerdyke, Fullaway!"

"Well?" demanded Allerdyke. "And so—"

"And so I want you to use your utmost ingenuity to find out if your cousin James gave that photo to Fullaway," continued Chettle. "We know very well that he was in touch with Fullaway before he went off to Russia—I have it in my notes that when Fullaway came to see you here in Hull, at the Station Hotel, the day of your cousin's death, he told you that he and Mr. James Allerdyke had been doing business for a couple of years, and that they'd last met in London about the end of March, just before your cousin set off on his journey to Russia. Is that correct?"

"Quite correct—to the letter," answered Allerdyke.

"Very well," said Chettle. "Now, according to you, that 'ud be not so very long after you took that snapshot of your cousin? So, he'd probably have the third print of it—the one we've just been looking at—on him when he was in London at that time?"

"Very likely," assented Allerdyke.

"Then," said Chettle with great eagerness, "try, Mr. Allerdyke, try your best and cleverest to find out if he gave it to Fullaway. You can think—you with a sharp brain!—of some cunning fashion of finding that out. What?"

"I don't know," replied Allerdyke, slowly and doubtfully. He possessed quite as much ingenuity as Chettle credited him with, but his own resourcefulness in that direction only inclined him to credit other men with the possession of just the same faculty. "I don't know about that. If James did give that print to Fullaway, and if Fullaway made use of it as you think, Fullaway'll be far too cute ever to let on that it was given to him. See!"

"I see that—been seeing it all through," answered Chettle. "All the same, there's ways and means. Think of something—you know Fullaway a bit by this time. Try it!"

"Oh, I'll try it, you bet!" exclaimed Allerdyke. "I'll try it for all it's worth, and as cleverly as I can. In fact, I've already thought of a plan, and if you don't want me any more just now, I'll go to the post-office and send off a telegram that's something to do with it."

"Nothing more now, sir," answered Chettle. "But look here—you're not going back to town to-night?"

"Why, that's just what I meant to do," replied Allerdyke. "There's naught to stop here for, is there?"

"I'm expecting a message from the Christiania police some time this afternoon or evening," said Chettle. "I cabled to them yesterday making full inquiries about Lydenberg—he represented himself here, to Dr. Orwin and the police-surgeons especially, as being a medical man in practice in Christiania, who had come across to Hull on some entirely private family business. Now, we've made the most exhaustive inquiries here in Hull—there isn't a soul in the town knows anything whatever of Lydenberg! I'm as certain as I am that I see you that he'd no business here at all—except to kill and rob your cousin. And so, of course, we want to know if he really was what he said he was, over there. I pressed upon the Christiania police to let me know all they could within thirty-six hours. So if you'll stop the night here, I'll likely be able to show you their reply to me."

"Right!" answered Allerdyke. "I'll put up at the Station Hotel. You come and have your dinner with me there at seven o'clock."

"Much obliged, Mr. Allerdyke," replied Chettle. "I'll come."

Then Allerdyke went off to the General Post Office and sent a telegram to his housekeeper in Bradford—

"Send off at once by registered parcel post to me at Waldorf Hotel, London, the morocco-bound photograph album lying on right-hand corner of my writing-desk in the library.—MARSHALL ALLERDYKE."

He went out of the post-office laughing cynically. Bit by bit things were coming out, he said to himself as he strolled away towards the hotel; link after link the chain was being forged. But around whom, in the end, was it going to be fastened? It was the first time in his life that he had ever been brought face to face with crime, and the seeking out of the criminal was beginning to fascinate him.

"Egad, it's a queer business!" he muttered. "A thread here, a thread there!—Heaven knows what it'll all come to. But this Chettle's a good 'un—he's like to do things."

Chettle joined him in the smoking-room of the hotel at a quarter to seven, and immediately produced a telegram.

"Came half an hour ago," he said as they sat down in a corner. "Nobody but myself seen it up to now. And—it's just what I expected. Read it."

Allerdyke slowly read the message through, pondering over it—

"We have made fullest inquiries concerning Lydenberg. He was certainly not in practice here either under that or any other name. Nothing is known of him as a resident in this city. We have definitely ascertained that he came to Christiania from Copenhagen, by land, via Lund and Copenhagen, arriving Christiania May 7th, and that he left here by steamship Perisco for Hull, May 10th."

"You notice the dates?" observed Chettle. "May 7th and 10th. Now, it was on May 8th that your cousin wired to Fullaway from Christiania, Mr. Allerdyke—there's no doubt about it! This man, Lydenberg, whoever he is or was, was sent to waylay your cousin at Christiania—sent from London. I've worked it out—he went overland—Belgium, Holland, Germany, Denmark, Sweden, Norway. Sounds a lot—but it's a quick journey. Sir—he was sent! And the sooner we find out about that photograph the better."

"I'm at work," answered Allerdyke. "Leave it to me."

He found his morocco-bound photograph album awaiting him when he arrived at the Waldorf Hotel next day, and during the afternoon he took it in his hand and strolled quietly and casually into Franklin Fullaway's rooms. Everything there looked as he had always seen it—Mrs. Marlow, charming as ever, was tapping steadily at her typewriter: Fullaway, himself a large cigar in his mouth, was reading the American newspapers, just arrived, in his own sanctum. He greeted Allerdyke with enthusiasm.

"Been away since yesterday, eh?" he said, after warm greetings. "Home?"

"Aye, I've been down to Yorkshire," responded Allerdyke offhandedly. "One or two things I wanted to see to, and some things I wanted to get. This is one of 'em."

"Family Bible?" inquired Fullaway, eyeing the solemnly bound album.

"No. Photos," answered Allerdyke. He was going to test things at once, and he opened the book at the fateful page. "I'm a bit of an amateur photographer," he went on, with a laugh. "Here's what's probably the last photo ever taken of James. What d'ye think of it?"

Fullaway glanced at the photograph, all unconscious that his caller was watching him as he had never been watched in his life. He waved his cigar at the open page.

"Oh!" he said airily. "A remarkably good likeness—wonderful! I said so when I saw it before—excellent likeness, Allerdyke, excellent! Couldn't be beaten by a professional. Excellent!"

Marshall Allerdyke felt his heart beating like a sledgehammer as he put his next question, and for the life of him he could not tell how he managed to keep his voice under control.

"Ah!" he said. "You've seen it before, then? James show it to you?"

Fullaway nodded towards the door of the outer room, from which came the faint click of the secretary's machine.

"He gave one to Mrs. Marlow the very last time he was here." he answered. "They were talking about amateur photography, and he pulled a print of that out of his pocket and made her a present of it; said it couldn't be beaten. You're a clever hand, Allerdyke—most lifelike portrait I ever saw. Well—any news?"