SIR ANGUS KINROSS, Chief Commissioner of Police, stood gazing down, with a look of frowning perplexity, at the sheet of typewritten paper he held in his hand.

For what seemed a very long time to the other three people now present in the big light room overlooking the Embankment, he remained silent. But at last he exclaimed, "I think it very probable that this is a hoax—a stupid, cruel hoax!" And, as no one spoke, he added slowly, "Whether it be so or not can soon be ascertained."

He saw a look of almost convulsive relief flash over Laura Pavely's face. It was Laura who attracted Sir Angus in the little group of people which now stood before him. He knew that it was this beautiful, tragic-looking young woman who had insisted, against his strongly expressed wish and judgment, on offering the reward which had already brought a swarm of semi-lunatics and adventurers into the case. As for the other woman there, he only looked upon her as a friend of Mrs. Pavely.

Ladies in the painful position of Mrs. Pavely generally bring a sister, or a close female friend, with them to Scotland Yard.

Sir Angus was keenly interested in this business of the country banker's disappearance, more interested than he had been in any other matter of the kind for a long time. He had all the threads of the affair very clearly set out in his shrewd, powerful mind, and only that morning he had learnt something which he believed none of the three people now standing before him—Mrs. Pavely, Mrs. Winslow, and Lord St. Amant—knew, or were likely ever to know, except, of course, if certain eventualities made the fact important.

Sir Angus had just learnt that Godfrey Pavely had spent some hours of a day he had passed at York in the company of a woman, and both he and the very able man he had put in charge of the case, had made up their minds that here, at last, was the real clue to the banker's disappearance. Godfrey Pavely, so they argued at "The Yard," was certainly alive, and either on the Continent, or hidden snugly in some English or Scottish country town—not alone.

As so often happens, the fact that Mr. Pavely had been in York with a lady had come to light in a very simple way. When the fact of the well-known country banker's disappearance had been announced in the Press, the manager of the Yorkshire branch of a London bank had written to Scotland Yard, and stated that on a certain afternoon about a fortnight ago—he could not remember the exact day, unfortunately—he had seen Mr. Godfrey Pavely, of Pewsbury, in the company of a lady whom he, the bank manager, had naturally supposed to be Mrs. Pavely. He had looked at the banker with a good deal of interest, owing to the fact that he and Mr. Pavely had for a while worked in the same bank in Paris about fifteen years ago.

He had not met the couple face to face, he had seen them pass by from the window of his private room at the bank. He could swear to Mr. Pavely, but he had not paid any special attention to the lady—for one thing, she had had her veil down, and he, feeling sure that she was Mrs. Pavely, had not troubled to observe her very particularly.

Sir Angus had sent some one down to York to see this gentleman, but nothing of further value had been elicited, excepting, yes, that the lady had struck him as being young and attractive.

So it was that the extraordinary typewritten letter received by Mrs. Pavely that morning very much upset the calculations and the theories of Sir Angus and of his staff.

With frowning brow he sat down at his table and touched the electric bell which lay concealed close to his hand.

"Ask Mr. Dowden to come to me," and a minute later Mr. Dowden came in.

"I want to know anything you can tell me about Duke House, if indeed there is such a place as Duke House in Piccadilly. I can't remember the name."

But at once the other answered: "It's that big new building they've erected on the site of St. Andrews House. It fell in to the Crown on the death of the Duke of St. Andrews, and an American syndicate bought the site. Duke House, as they call it, was only opened last October. The lower storeys are big bachelor flats, and the top half of the building contains offices. Mr. Biddle, the American millionaire, has taken the first floor, but he hasn't settled in yet, and I don't think any of the offices have been let at all. They are asking very big rents, and they are justified, as it's one of the finest sites in the West End."

"I want you to get through to the porter of Duke House. Find out for me whether they have got an office let to a man—a Portuguese merchant I take him to be, of the name of Fernando Apra." He spelt out the name. "If you have any difficulty in getting the information, just go up there yourself in a taxi, and find out. But I'd like you to go back into your own rooms and try by telephone first."

There followed a long, painful ten minutes, during which Sir Angus, though as a rule he was a man of few words, tried to while away the time by explaining to the three people who were there why he thought it unlikely that the letter was genuine.

"You'd be amazed," he said, "to know the number of letters we receive purporting to contain important information which turn out to be false in every particular. There must be a whole breed of individuals who spend their time in writing annoying, futile letters, which, even if signed, are very seldom signed by the writer's real name. Some of those people are actuated by vulgar, stupid spite; others are hypnotised by the thought of a reward. And then, again, such letters are often written by people who have a grudge against the police, or, even more often, by some one who has a grudge against some ordinary person who has, maybe, done them a bad turn, or to whom they have done a bad turn! In the last few days we've had innumerable letters, from all over the kingdom, concerning Mr. Pavely's disappearance. It is just possible that this man"—he looked down again at the sheet of typewritten paper—"has an office in Duke House, but I think it very unlikely that Mr. Godfrey Pavely was even acquainted with him——"

The door opened.

"Yes, sir, the party in question has got an office there right enough, but he hasn't been at Duke House for some time—some three weeks, the porter said. He took the office late in October, and for a time he was there, on and off, a good deal. The porter don't quite know what his business is, but as far as he knows he gives him a good character. His office is right at the very top of the house, the only one let on that floor."

An unpleasant little trickle of doubt came over Sir Angus's mind. When he had first read the typewritten letter, he had doubted very much if there was such a building in existence as Duke House, Piccadilly. Then, after he had heard that the place was there, after, as a matter of fact, it had been recalled to his memory by his subordinate, he had fallen back on the belief that there would be no person of the name of Fernando Apra to be found in Duke House.

He now fell back on a third position. Doubtless this extraordinary letter had been written by some enemy of the man Apra who wished to cause him the unpleasantness of a visit from the police.

After a few moments' thought Sir Angus Kinross proposed something which none of the three people there knew to be a most surprising departure from his usual rule.

"What would you say, Lord St. Amant, if you and I were to go up there now, to Duke House—accompanied, of course, by two of my men? That, at any rate, would put an end to Mrs. Pavely's suspense. If she doesn't mind doing so, Mrs. Pavely and her friend can wait here, in my private room."

To Lord St. Amant the proposal seemed a most natural one. "I think that's a very good idea!" he exclaimed, and then he saw Katty's eyes fixed imploringly on his face.

Why, of course——!

He beckoned to Sir Angus, and the two men walked over to the big window overlooking the Embankment. "If it would not be greatly out of order," he muttered, "I think it might be a good thing if Mrs. Winslow—that is Mrs. Pavely's friend—were to go with us to Duke House. She might be useful—she has known Mr. Godfrey Pavely all her life."

Sir Angus looked very much surprised. "Of course she could come," he said hesitatingly. "Mrs. Winslow? I didn't realise that this lady is Mrs. Winslow. Didn't I see a letter written to her by Mr. Godfrey Pavely? She has some odd Christian name—if it's the person I have in my mind."

"Her Christian name is Katty," said Lord St. Amant quickly.

"Yes, that was it—'My dear Katty.' I remember now. It was a letter about an investment, written on the 30th of December, if I'm not mistaken. Certainly she can come with us. I have my car downstairs—she could drive in my car, and wait in it while we make the investigation."

The two came back to where the ladies were sitting, silently waiting.

"I have suggested to Sir Angus that it might be useful if Mrs. Winslow came with us—and you too, my dear Laura, if you desire to do so, of course."

But Laura shook her head, and an expression of horror came into her face. "Oh no," she exclaimed. "I would much rather stay here!"

Katty had already got up, and was drawing on the gloves she had taken off. She felt strung up, fearfully excited—and very, very grateful to Lord St. Amant.

She was quite unaware that for the first time the Commissioner of Police was looking at her with attention.

There were two entrances to Duke House, the one giving access to the four spacious flats, of which so far only one had been let, while the other simply consisted of a porter's lodge and a lift shooting straight up to the offices which were above the flats.

And now, within ten minutes of their leaving Scotland Yard, they were all standing just within the second door, filling up the small space in front of the lift, for Mrs. Winslow at the last moment had begged to be allowed to get out of the car. "I don't feel as if I could sit there—waiting," she had exclaimed, and after a moment's hesitation Sir Angus allowed the plea.

Lord St. Amant noticed with interest that the Police Commissioner took no part in the preliminary proceedings. He left everything to the elder of the two men he had brought with him. Still, he lent a very attentive ear to what his subordinate was saying to the porter, and to the porter's answers.

"I expect that it was you who answered the telephone message I sent half an hour ago, eh?"

"Yes, of course I did—you mean about Mr. Apra here? Well, I told you then everything there is to say about him. He's a foreigner, of course—but a very pleasant-mannered gentleman. He took an office on the second day we was open. For a while he was here a good bit most days, and quite a number of people came to see him on business. Then he went abroad, I fancy I heard him say, and his office was shut up. He wouldn't let any one go in, not even to clean it, unless he was there. He explained as how his business was very secret—something to do with a Concession. He was nervous lest other folk should get hold of the idea."

"When was he here last?"

"Well, it's difficult for me to remember such a thing as that—I can't be sure that I could say he was here within the last fortnight, or perhaps ten days ago. Two or three people have called to see him. One gentleman came by appointment—I do remember that, because he'd been several times, and mostly this Mr. Apra was in to see him. But I don't see what call you have to ask me all these questions?"

The Scotland Yard man bent forward and said something in a low voice, and the porter exclaimed, with an air of astonishment, "What? You don't mean to say the gentleman's 'wanted'?"

Then the detective said something else in a joking way, and the porter shook his head. "I haven't got a key! He had another lock put on. Lots of business gentlemen do that." And then he asked anxiously, "D'you see any objection to my telephoning to Messrs. Drew & Co.—they're the agents, you know? 'Twould make me more comfortable in my own mind, because then I shouldn't get blamed—whatever happened. They'd send some one along in about five minutes—they've got a West End office."

The Scotland Yard official looked round for instructions from Sir Angus, and the latter imperceptibly nodded.

"All right—we'll wait five minutes. I've brought some tools along."

"Tools?" The porter stared at him.

"Sometimes, you know, we do find it necessary to burst open a door!"

The five minutes—it was barely more—seemed the longest time Katty had ever spent in waiting.

Lord St. Amant took pity on her obvious unease and anxiety. He walked out with her to the street, and they paced quickly up and down in the cold, wintry air.

"Do you think we shall find anything?" she murmured at last.

He answered gravely, "I confess that the whole thing looks very queer to me. I haven't lived to my time of life without becoming aware that amazing, astounding things do happen. Perhaps I am over-influenced by the fact that years and years ago, when I was a boy, a school-fellow of mine, of whom I was very fond, did shoot himself accidentally with a pistol. He was staying with us, and he had gone on in front of me into the gun-room—and I—I went in and found him lying on the ground—dead."

"How horrible!" murmured Katty. "How very horrible!" and her face blanched.

As they turned yet once more, a taxi drove quickly up to the door of Duke Mansion, and a young, clean-shaven man jumped out.

Instinctively he addressed himself to Sir Angus Kinross: "About this tenant of ours—Mr. Fernando Apra? To the best of my belief he is a perfectly respectable man. He gave a very good reference, that of a big Paris banker, and with us, at any rate, he was quite frank about his business. He has obtained a gambling concession from this new Portuguese Government, and he came to London to try and raise money for the building of a Casino, and so on. He's an optimistic chap, and his notion is to create a kind of Portuguese Monte Carlo. He told us quite frankly that he didn't intend to keep the office going here for more than six months, or possibly a year, and we arranged that he should be able to surrender his three years' lease—we don't let these rooms under a three years' agreement—on the payment of a rather substantial fine. I think the porter is sure to have a key which will admit you into his room—I understand you want to get into his office?"

And then, at last, Sir Angus answered, rather drily, "The porter cannot admit us to the office, for this Mr. Fernando Apra has had a second lock fitted. It seems he never allowed any one access to the room—unless he happened to be there himself."

"Well, he had plans there—plans of this Concession, and he was very secretive, as are so many foreigners. Still, he impressed both me and my father more favourably than do most foreigners we come across. As a matter of fact, we twice lunched with him at the Berkeley. He is a man with a tremendous flow of good spirits—speaking English very well, though of course with a foreign accent. Has he got into any trouble?" he looked curiously at the gentleman standing before him. He was not aware of Sir Angus Kinross's identity, but he knew that he was from Scotland Yard.

"We shall know more about that when we have forced open the door of his office. I presume you would like to be present?"

And the young man nodded. A grave, uneasy expression came over his face; he wondered if he had said too much of his pleasant client, and that client's private affairs."