their deductions, that the burglar had commenced proceedings on No. 26, Phillimore Terrace, and had then gone on, probably climbing over the garden walls between the houses to No. 22, where he was almost caught in the act by Robertson. The facts were simple enough, but the mystery remained as to the individual who had managed to glean the information of the presence of the diamonds in both the houses, and the means which he had adopted to get that information. It was obvious that the thief or thieves knew more about Mr. Knopf's affairs than Mr. Shipman's, since they had known how to use Mr. Emile Knopf's name in order to get his brother out of the way.
"It was now nearly ten o'clock, and the detectives, having taken leave of Mr. Shipman, went back to No. 22, in order to ascertain whether Mr. Knopf had come back; the door was opened by the old charwoman, who said that her master had returned, and was having some breakfast in the dining-room.
"Mr. Ferdinand Knopf was a middle-aged man, with sallow complexion, black hair and beard, of obviously Hebrew extraction. He spoke with a marked foreign accent, but very courteously, to the two officials, who, he begged, would excuse him if he went on with his breakfast.
"'I was fully prepared to hear the bad news,' he explained, 'which my man Robertson told me when I arrived. The letter I got last night was a bogus one; there is no such person as J. Collins, M.D. My brother had never felt better in his life. You will, I am sure, very soon trace the cunning writer of that epistle—ah! but I was in a rage, I can tell you, when I got to the Metropole at Brighton, and found that Emile, my brother, had never heard of any Doctor Collins.
"'The last train to town had gone, although I raced back to the station as hard as I could. Poor old Robertson, he has a terrible cold. Ah yes! my loss! it is for me a very serious one; if I had not made that lucky bargain with Mr. Shipman last night I should, perhaps, at this moment be a ruined man.
"'The stones I had yesterday were, firstly, some magnificent Brazilians; these I sold to Mr. Shipman mostly. Then I had some very good Cape diamonds—all gone; and some quite special Parisians, of wonderful work and finish, entrusted to me for sale by a great French house. I tell you, sir, my loss will be nearly £10,000 altogether. I sell on commission, and, of course, have to make good the loss.'
"He was evidently trying to bear up manfully, and as a business man should, under his sad fate. He refused in any way to attach the slightest blame to his old and faithful servant Robertson, who had caught, perhaps, his death of cold in his zeal for his absent master. As for any hint of suspicion falling even remotely upon the man, the very idea appeared to Mr. Knopf absolutely preposterous.
"With regard to the old charwoman, Mr. Knopf certainly knew nothing about her, beyond the fact that she had been recommended to him by one of the tradespeople in the neighbourhood, and seemed perfectly honest, respectable, and sober.
"About the tramp Mr. Knopf knew still less, nor could he imagine how he, or in fact anybody else, could possibly know that he happened to have diamonds in his house that night.
"This certainly seemed the great hitch in the case.
"Mr. Ferdinand Knopf, at the instance of the police, later on went to the station and had a look at the suspected tramp. He declared that he had never set eyes on him before.
"Mr. Shipman, on his way home from business in the afternoon, had done likewise, and made a similar statement.
"Brought before the magistrate, the tramp gave but a poor account of himself. He gave a name and address, which latter, of course, proved to be false. After that he absolutely refused to speak. He seemed not to care whether he was kept in custody or not. Very soon even the police realized that, for the present, at any rate, nothing could be got out of the suspected tramp.
"Mr. Francis Howard, the detective, who had charge of the case, though he would not admit it even to himself, was at his wits' ends. You must remember that the burglary, through its very simplicity, was an exceedingly mysterious affair. The constable, D 21, who had stood in Adam and Eve Mews, presumably while Mr. Knopf's house was being robbed, had seen no one turn out from the cul-de-sac into the main passage of the mews.
"The stables, which immediately faced the back entrance of the Phillimore Terrace houses, were all private ones belonging to residents in the neighbourhood. The coachmen, their families, and all the grooms who slept in the stablings were rigidly watched and questioned. One and all had seen nothing, heard nothing, until Robertson's shrieks had roused them from their sleep.
"As for the letter from Brighton, it was absolutely commonplace, and written upon note-paper which the detective, with Machiavellian cunning, traced to a stationer's shop in West Street. But the trade at that particular shop was a very brisk one; scores of people had bought note-paper there, similar to that on which the supposed doctor had written his tricky letter. The handwriting was cramped, perhaps a disguised one; in any case, except under very exceptional circumstances, it could afford no clue to the identity of the thief. Needless to say, the tramp, when told to write his name, wrote a totally different and absolutely uneducated hand.
"Matters stood, however, in the same persistently mysterious state when a small discovery was made, which suggested to Mr. Francis Howard an idea, which, if properly carried out, would, he hoped, inevitably bring the cunning burglar safely within the grasp of the police.
"That was the discovery of a few of Mr. Knopf's diamonds," continued the man in the corner after a slight pause, "evidently trampled into the ground by the thief whilst making his hurried exit through the garden of No. 22, Phillimore Terrace.
"At the end of this garden there is a small studio which had been built by a former owner of the house, and behind it a small piece of waste ground about seven feet square which had once been a rockery, and is still filled with large loose stones, in the shadow of which earwigs and woodlice innumerable have made a happy hunting ground.
"It was Robertson who, two days after the robbery, having need of a large stone, for some household purpose or other, dislodged one from that piece of waste ground, and found a few shining pebbles beneath it. Mr. Knopf took them round to the police-station himself immediately, and identified the stones as some of his Parisian ones.
"Later on the detective went to view the place where the find had been made, and there conceived the plan upon which he built big cherished hopes.
"Acting upon the advice of Mr. Francis Howard, the police decided to let the anonymous tramp out of his safe retreat within the station, and to allow him to wander whithersoever he chose. A good idea, perhaps—the presumption being that, sooner or later, if the man was in any way mixed up with the cunning thieves, he would either rejoin his comrades or even lead the police to where the remnant of his hoard lay hidden; needless to say, his footsteps were to be literally dogged.
"The wretched tramp, on his discharge, wandered out of the yard, wrapping his thin coat round his shoulders, for it was a bitterly cold afternoon. He began operations by turning into the Town Hall Tavern for a good feed and a copious drink. Mr. Francis Howard noted that he seemed to eye every passer-by with suspicion, but he seemed to enjoy his dinner, and sat some time over his bottle of wine.
"It was close upon four o'clock when he left the tavern, and then began for the indefatigable Mr. Howard one of the most wearisome and uninteresting chases, through the mazes of the London streets, he ever remembers to have made. Up Notting Hill, down the slums of Notting Dale, along the High Street, beyond Hammersmith, and through Shepherd's Bush did that anonymous tramp lead the unfortunate detective, never hurrying himself, stopping every now and then at a public-house to get a drink, whither Mr. Howard did not always care to follow him.
"In spite of his fatigue, Mr. Francis Howard's hopes rose with every half-hour of this weary tramp. The man was obviously striving to kill time; he seemed to feel no weariness, but walked on and on, perhaps suspecting that he was being followed.
"At last, with a beating heart, though half perished with cold, and with terribly sore feet, the detective began to realize that the tramp was gradually working his way back towards Kensington. It was then close upon eleven o'clock at night; once or twice the man had walked up and down the High Street, from St. Paul's School to Derry and Toms' shops and back again, he had looked down one or two of the side streets and—at last—he turned into Phillimore Terrace. He seemed in no hurry, he oven stopped once in the