When the manager, much appeased and relieved in mind, had gone, Fullaway tapped at the door of the bedroom, summoned the pretty chambermaid, and handed her the rosewood box.

"Put this back exactly where Mademoiselle has kept it since she came here," he commanded. "Now you yourself—you're going to stay in the rooms until she comes back from the concert? That's right—if she returns before my friend and I come up again, tell her that we shall present ourselves at five minutes to eleven. Come downstairs, Allerdyke," he proceeded, leading the way from the room. "We must book rooms for the night here, so we'll send to the station for our things and make our arrangements, after which we'll smoke a cigar and talk—I am beginning to see chinks of daylight."

He led Allerdyke down to the office, completed the necessary arrangements, and went on to the smoking-room, in a quiet corner of which he pulled out his cigar-case.

"Well?" he said. "What do you think now?"

"I think you're a smart chap," answered Allerdyke bluntly. "You did all that very well. I said naught, but I kept an eye and an ear open. You'll do."

"Very complimentary!—but I wasn't asking you what you thought about me," said Fullaway, with a laugh. "I'm asking you what you think of the situation, as illuminated by this last episode?"

"Well, I'm still reflecting on what you said to that manager chap," answered Allerdyke. "You really think this young woman has lost her jewels?"

"Oh, no doubt, no doubt at all," replied Fullaway. "Mademoiselle is impetuous, impulsive, demonstrative, much given to insisting on her own way, but she's absolutely honest and truthful, and I've no doubt whatever—none!—that she's been robbed. But—not here. She never brought those jewels here. They were not in that box when she came here. Mademoiselle, my dear sir, was relieved of those jewels either on the steamer, as she crossed from, Christiania to Hull, or during the few hours she spent at the Hull hotel. The whole thing—the robbery from your cousin, the robbery from Mademoiselle de Longarde—is all the work of a particularly clever and brilliant gang of international thieves; and, by the holy smoke, sir, we've got our hands full! For there isn't a clue to the identity of the operators, so far, unless the lady with whom we are going to sup can help us to one."

Allerdyke ruminated over this for a moment or two. Then, after lighting the cigar which Fullaway had offered him, he shook his head—in grim affirmation.

"I shouldn't wonder," he said. "Certainly, it seems a big thing. You're figuring on its having been a carefully concocted scheme? No mere chance affair, eh?"

"This sort of thing's never done by chance," responded the American. "This is the work of very clever and accomplished thieves who somehow became aware of two facts. One, that your cousin was bringing with him to England the jewels of the Princess Nastirsevitch. The other, that Mademoiselle ZÉlie de Longarde carried her pearls and diamonds in an innocent-looking rosewood box. My dear sir! you observed that I examined that box with seeming carelessness—in reality, I was looking at it with the eye of a trained observer. I am one of those people who, from having knocked about the world a lot, engaging in a multifarious variety of occupations, have picked up a queer scrap-heap of knowledge, and I will lay you any odds you like that I am absolutely correct in affirming that the box which I just now handed to Maggie, the chambermaid, was newly made by a Russian cabinet-maker within the last four weeks!"

"For a purpose?" suggested Allerdyke.

"Just so—for a purpose," assented Fullaway. "That purpose being, of course, its substitution for the real original article. You did not handle the box which is now upstairs—it is carefully weighted, though it is empty. I believe—nay, I am sure, it contains a sheet of lead under its delicate lining of satin. That, of course, was to deceive Mademoiselle. You heard her say that the jewels were in her box at Christiania, and that she never opened the box until this evening here in Edinburgh? Very good—between here and Christiania somebody substituted the imitation box for the real one. Ah!—in all these great criminal operations there is nothing like sticking to the old, well-worn, tried-and-proved tricks of the trade!—they are like well-oiled, well-practised machinery. And now we come back to the real, great, anxious question—Who did it? And there, Allerdyke, we are at present—only at present, mind!—up against a very big, blank wall."

"On the other side of which, my lad, lies the secret of the murder of my cousin," said Allerdyke grimly. "Mind you that! That's what I'm after, Fullaway. Damn all these jewels and things, in comparison with that!—it's that I'm after, I tell you again, and a thousand times again. And I'm considering if I'm doing any good hanging round here after this singing woman when the probable sphere of action lies yonder away at Hull, eh?"

"The proper—not probable—sphere of action, my dear sir, is the supper-table to which we're presently going," answered Fullaway, with supreme assurance. "What the singing woman, as you call her, can tell us will most likely make all the difference in the world to our investigations. Remember the shoe-buckle! Have it ready to exhibit when I lead up to it. Then—we shall see."

The prima donna, back for her engagement at eleven o'clock, came in flushed and smiling—the extraordinary warmth and fervour of her reception by the audience which she had at first been so inclined to treat with scant courtesy had restored her to good humour, and when she had eaten a few mouthfuls of delicate food and drunk her first glass of champagne she began to laugh almost light-heartedly.

"Well, I suppose you've been doing your best, Fullaway," she said, with easy familiarity. "I declare you turned up at the very moment, for that fat Weiss would have been no good. But I'm still wondering how you came to be here, and what this gentleman—Mr. Allerdyke, is it?—is doing here with you. Allerdyke, now—well, that's the same name as that of a man I came across from Christiania with, and left at Hull."

Fullaway kicked Allerdyke under the table.

"You haven't heard of that Mr. Allerdyke since you left him at Hull, then?" he asked, gazing intently at their hostess.

"Heard? How should I hear?" asked the prima donna. "He was just a travelling acquaintance. All the same, I had certainly fixed up to see him in London on a business matter."

"You don't read the newspapers, then?" suggested Fullaway.

"Not unless there's something about myself in them," she answered, with an arch smile at Allerdyke.

"If you'd read this morning's papers, you'd have seen that the Mr. Allerdyke with whom you travelled—this gentleman's cousin, by the by—was found dead in his room at the hotel in Hull not so long after you quitted it," said Fullaway coolly. "In fact, he must have been dead when you passed his door on your way out."

The prima donna was genuinely shocked. She set down the glass which she was just lifting to her lips; her large, handsome eyes dilated, her lips quivered a little. She turned a look of sympathy on Allerdyke, who, at that moment, realized that she was a very beautiful woman.

"You don't say so!" she exclaimed. "Well, I'm really grieved to hear that—I am! Dead?—and when I left! Why, I was in his room that very night we reached Hull, having a talk on the business matter I mentioned just now—he was well enough and lively enough then, I'll swear. Dead!—why, what did he die of?"

The two men looked at each other. There was a brief pause; then Allerdyke slowly produced a small packet, wrapped in tissue-paper, from his waistcoat pocket. He laid it on the table at his side and looked at his hostess.

"I knew you had been in my cousin's room," he said. "You left or dropped your shoe-buckle there. I found it when I searched his room. Then the hotel manager showed me your wire. Here's the buckle."

He was watching her narrowly as he spoke, and his glance deepened in intensity as he handed over the little packet and watched her unwrap the paper. But there was not a sign of anything but a little surprised satisfaction in the prima donna's face as she recognized her lost property, and her eyes were ingenuous enough as she turned them on him.

"Why, of course, that's mine!" she exclaimed. "I'm ever so much obliged to you, Mr. Allerdyke. Yes, I wired to the hotel, in my proper name, you know—ZÉlie de Longarde is only my professional name. I didn't want to lose that buckle—it was part of a birthday present from my mother. But you don't mean to say that you travelled all the way to Edinburgh to hand me that! Surely not?"

"No!" replied Allerdyke. He wanted to take a direct share in the talking, and went resolutely ahead now that the chance had come. "No—not at all. I knew you'd come to Edinburgh—found it out from that chauffeur who was driving you when you and I met at Howden the night before last, and so I came on to find you. I want to ask you some questions about my cousin, and maybe to get you to come and give evidence at the inquest on him."

"Inquest!" she exclaimed. "I know what that means, of course. Why—you don't say there's been anything wrong?"

"I believe my cousin was murdered that night," answered Allerdyke. "So, too, does Fullaway there. And you were probably the last person who ever spoke to him alive. Now, you see, I'm a plain, blunt-spoken sort of chap—I ask people straight questions. What did you go into his room to talk to him about?"

"Business!" she replied, with a directness which impressed both men. "Mere business. He and I had several conversations on board the Perisco—I made out he was a clever business man. I want to invest some money—he advised me to put it into a development company in Norway, which is doing big things in fir and pine. I went into his room to look at some plans and papers—he gave me some prospectuses which are in that bag there just now—-I was reading them over again only this evening. That's all. I wasn't there many minutes—and, as I told you, he was very well, very brisk and lively then."

"Did he show you any valuables that he had with him—jewels?" asked
Allerdyke brusquely.

"Jewels! Valuables!" she answered. "No—certainly not."

"Nor when you were on the steamer?"

"No—nor at any time," she said. "Jewels?—why—what makes you ask such a question?"

"Because my cousin had in his possession a consignment of such things, of great value, and we believe that he was murdered for them—that's why," replied Allerdyke. "He had them when he left Christiania—he had them when he entered the Hull hotel—"

Fullaway, who had been listening intently, leant forward with a shake of his head.

"Stop at that, Allerdyke," he said. "We don't know, now, that he did have them when he entered the hotel at Hull! He mayn't have had. Miss Lennard—we'll drop the professional name and turn to the real one," he said, with a bow to the prima donna—"Miss Lennard here thinks she had her jewels in her little box when she entered the Hull hotel, and also when she came to this hotel, here in Edinburgh, but—"

"Do you mean to say that I hadn't?" she exclaimed. "Do you mean—"

"I mean," replied Fullaway, "that, knowing what I now know, I believe that both you and the dead man, James Allerdyke, were robbed on the Perisco. And I want to ask you a question at once. Where is your maid!"

Celia Lennard dropped her knife and fork and sat back, suddenly turning pale.

"My maid!" she said faintly. "Good heavens! you don't think—oh, you aren't suggesting that she's the thief? Because—oh, this is dreadful! You see—I never thought of it before—when she and I arrived at Hull that night she was met by a man who described himself as her brother. He was in a great state of agitation—he said he'd rushed up to Hull to meet her, to beg her to go straight with him to their mother, who was dying in London. Of course, I let her go at once—they drove straight from the riverside at Hull to the station to catch the train. What else could I do? I never suspected anything. Oh!"

Fullaway leaned across the table and filled his hostess's glass.

"Now," he said, motioning her to drink, "you know your maid's name and address, don't you? Let me have them at once, and within a couple of hours we'll know if the story about the dying mother was true."