There was no mistaking the fact that it was Anstruther who was standing outside and speaking in tones which denoted that he was not altogether pleased with himself. It might have been a coincidence, or, at the same time, it might have been intentional; though the latter suggestion did not appear probable.

"Surely he can't have found us out yet," Jack cried. "If he had done so it would hardly be policy to make so much noise about it. What do you think, Mr. Bates?"

Bates responded cautiously that he did not know what to think. The real solution came from Seymour.

"There is no coincidence about it at all," he said. "We know perfectly well that Anstruther is a clever criminal, but even clever criminals cannot bring off important campaigns without the aid of subordinates. I have not taken up my quarters here entirely by accident, though, of course, it was necessary for me to be as far off the beaten track as possible. I have seen Anstruther here on more than one occasion, and I think you will find he has come to consult one of his satellites."

"There must be a good few shady people here," Bates observed, "though I don't know much about the locality."

Seymour explained that there were plenty of doubtful characters living in the tenement. He suspected at least three burglars who had rooms on the same floor. Probably Anstruther was looking for one of these, and for some reason or other the fellow had denied himself. The loud tones had ceased now, and it was evident that Anstruther had either left the house or found the man of whom he was in search. The discovery, however, was too important to be allowed to rest like that, and Bates had a proposition to make. He suggested the advisability of putting one of his own spies on to watch Anstruther and keep an eye upon him for the rest of the day. There would not be the slightest uncertainty about this, seeing that Anstruther was so well known to the police generally.

Bates crept carefully away, and returned presently with the information that Anstruther was still on the premises.

"I met one of my men in the street," he explained. "He was just back from a job this way, and spotted Anstruther coming in here. Our friend is not likely to shake off the fellow that I have put upon his track. Meanwhile, we are wasting time here."

Seymour was decidedly of the same opinion. A minute or two later the trio made their way into the street, leaving Seymour alone. He had been informed by Bates that he would be kept posted of Anstruther's movements by means of special messenger, and that his services would be called upon if necessary. Thus assured, Seymour went back to his mysterious business with the handcuffs and file, quite content to wait till his time came.

It was quite dark before the first message arrived. Anstruther had stayed where he was till seven o'clock, after which he had gone out and called at a neighboring shop, which was kept by a man engaged in the occupation of making brass plates. This, so the message said, was merely a blind for the manufacture of the finest specimens of burglars' tools. Anstruther had entered the shop with nothing in his hand, but had emerged presently carrying a small square parcel which might have been a picture frame. Thus encumbered, he had returned to the tenement, and was now closeted in the set of rooms below Seymour's with a man called Gillmore, otherwise "Simple Charlie," a cracksman who stood quite at the head of his profession.

Seymour's eyes gleamed as he glanced over the letter. He felt that he must be up and doing something. It occurred to him as a good idea to make an attempt to be present at the interview between Anstruther and his confederate. It was absolutely dark now, so that Seymour had no hesitation in raising his sitting-room window, which faced the back of the house, and seeking to find some means for entering the set of rooms below.

So far as he could see at first, the thing appeared to be impossible. His quick eye noted the fact that a powerful light burned in the room below, for the shadow of it was thrown strongly upon the blank wall opposite. To the left of Seymour's window was a large drain pipe used for conveying the rain water from the roof to the sewer below. It was an easy matter for Seymour to lash a rope firmly to the floor with the aid of a handspike, and to gently lower himself to the floor below by means of the pipe. The business was no easy one when it came to climbing proper, and only a strong man like Seymour could have possibly done it. He dangled thus perilously in mid air, working his way down inch by inch, till at length his feet rested on the sill of the window below.

As he had half expected, the window was without a catch, which was quite in accordance with most of the fittings in the tenement. Leaving his rope to dangle harmlessly within reach until it would be required again, Seymour passed coolly into the room. He rubbed a match cautiously, and by the aid of it saw that he was in a small bedroom evidently devoted to the uses of some bachelor, for the bed had been made in a most perfunctory way, and the floor was liberally strewn with tobacco ash. Lying on the table was a plan of some large mansion, with footnotes here and there plainly denoting the fact that the house had been marked down for some ingenious burglary. Seymour smiled to himself.

He had evidently found his way into the quarters of which he was in search. Listening intently, with his ear closely glued against the wall, he could detect the sound of voices on the other side. He was not personally acquainted with the voice of "Simple Charlie," but the round, full tones of Anstruther were quite familiar to him.

Seymour was, however, not content merely to listen to what was going on. Very softly he made his way from the bedroom into the passage beyond. The door of the next room was not closed; indeed, there was no reason for the precaution, seeing that the door at the end of the passage was locked. There was a pungent smell of tobacco, mingled with the odor of a good cigar, and presently the loud pop of a cork and the fizzing gurgle of what Seymour rightly guessed to be champagne. By creeping close and twisting a little sideways, Seymour got a fairly good view of the room.

He could see Anstruther lounging in a comfortable armchair, a cigar in his mouth, apparently quite at home in his humble surroundings. The other man was sucking moodily at a short pipe, and glanced uneasily at his companion. He was not much like the commonly accepted type of burglar, being slight and da............