Zimburg pulled the lamp across the table, and through his glasses carefully scrutinized the features of the violinist. "Very strange," he muttered; "it is not often that I am puzzled. Offhand I should have said that I have never seen this face before, but the more I look at it, the more certain I am that the features are quite familiar to me. At the same time there is some subtle change which baffles me. It may be the eyes, or the nose and the mouth--that it is impossible to say. Anyway, I should be prepared to arrest this man on suspicion, and take the risk of finding out all about him afterwards."

"I suppose any slight alteration makes a difference in the photograph?" Jack asked. "After all said and done, photography is a very weak reed to lie upon. Can't you tell us exactly what is puzzling you?"

Zimburg threw up his hands with a suggestion of despair. A sudden light flashed across Jack's mind. He recollected that Padini, so far as the stage was concerned, appeared with a clean face, but in private life it had been his whim to adopt a moustache strictly on the lines of that worn by the German Emperor. It was apparently an insane thing to do, and savored more of conceit than of anything else, but no doubt the thing had its advantages.

"Do you happen to have such a thing as a paint-box and a brush on the premises?" Jack asked. "If so, I think I shall be in a position to jog Mr. Zimburg's memory."

As it happened, the necessary implements were there to hand. There were occasions, Bates explained, when such things were necessary. Now and then some sprig of the nobility who had dined not wisely but too well found himself in the cells in a more or less dilapidated condition, and here it was that the paint-box came in. Black eyes and discolored faces and that kind of thing, Bates explained. "I assure you that a dash or two of paint makes all the difference in the world."

Jack smiled as he bent over the photograph, and with a few subtle touches decorated the face with a fierce blond moustache. He handed the card over without comment to Zimburg. The little man's face fairly beamed with delight.

"Ah! but you are a clever gentleman," he cried. "Now I know our friend. Yes, yes, but he is a very clever man. And older than he looks, mind you; that fellow has eluded the Continental police for years. It would be absurd to try and give his real name, for probably he has forgotten it himself. Yes, I have heard of his playing before; not that I regarded him as quite good enough for a public platform. Wherever that man goes, roguery follows as a matter of course. Depend upon it, his appearance here means mischief. I will have him carefully watched, and before long I shall have the pleasure of laying him by the heels."

"Don't do that, at least until you are absolutely obliged to," Jack said eagerly. "We are interested, deeply interested, in the movements of Signor Padini. It is more or less of a private matter, but if you could provide us with some means of getting a hold on that fellow we should be exceedingly obliged to you."

Zimburg promised to do his best, and departed. For some little time Rigby and Bates stood discussing the most recent developments of the case, whilst Jack sat in a thoughtful attitude, evidently puzzling something out.

"Do you call Zimburg a really clever detective?" he asked at length. "It seems to me that he has a poor memory for faces. For instance, he had not the slightest idea who the man Padini was till that moustache was added to the face of the photograph."

Bates, eager in defense of his colleagues, remarked that a little thing like that often made a vast difference.

"That is one of the great advantages of the Bertillon system," he explained. "I don't care how clever a man may be--and when I speak of a clever man I mean a policeman in this instance--he is often utterly deceived by some slight physical change. Take the case of the late Charles Peace if you like. I understand that he could alter the expression and even the shape of his face entirely. Make your mind quite easy, for Zimburg will work it all out like some ingenious puzzle. I suppose you are aware of the fact that the London and Paris police have thousands of careful records made of the measurements of well-known criminals?"

"But Zimburg can't very well measure Padini," Rigby argued. "He can't make him drunk, or anything of that kind."

"No, but he can have him arrested on some faked-up charge," Bates laughed. "That little game has been played more than once when we wanted the measurements of some clever criminal who had never passed through our hands."

"That is very ingenious," Rigby said, "and I shan't forget it. If facts like those were more widely known, I fancy you would get more assistance from the Press."

Bates emphatically repudiated the suggestion.

"I have often heard you say, in fact it is rather a fruitful source of complaint to the police, that the newspapers do them more harm than good," Jack said reflectively; "but I think I can see a way whereby the Press could give you a good leg-up in the case of this Belgrave Gardens mystery. Dick, is it too late to get a paragraph inserted in to-morrow's Planet?"

"Oh, dear, no," Rigby explained. "Probably no paper in London goes to bed later than we do. We make it a point of keeping open till the last possible minute, and we have a good hour before us yet. But what are you driving at?"

"Well, it is this way. It is pretty clear that one of the thieves was wearing that embroidered scarf which was also claimed by Mrs. Montague. Probably there were two such mufflers, but that does not affect my argument. Of course, a description of this affair will appear in to-morrow's Planet,but I should like to embroider on it a bit. Suppose we add to the report a paragraph to the effect that the thief left a marvelous wrap behind him. We could say that it was absolutely unique, and all that sort of thing, just the sort of silly gossip that your readers are so fond of. We could hint that the scarf still remains at Belgrave Gardens for identification. Now it is a thousand to one this paragraph reaches the eye of the thief, or is brought to his notice. This being so, he will lose no opportunity of getting the wrap back again. All you have to do is to keep the house carefully under observation, and your man falls into your hands like a ripe blackberry. What does the inspector think of our little scheme?"

Bates pondered the matter a moment or two, and then cautiously remarked that at any rate there could be no harm in it. Whereupon the two friends went away together, and half-an-hour later a ............