CHAPTER VI

  ALL HE KNEW

  "The tramp was missing," continued the man in the corner, "and Mr.Francis Howard tried to find the missing tramp. Going round to thefront, and seeing the lights at No. 26 still in, he called upon Mr.Shipman. The jeweller had had a few friends to dinner, and was givingthem whiskies-and-sodas before saying good night. The servants had justfinished washing up, and were waiting to go to bed; neither they nor Mr.Shipman nor his guests had seen or heard anything of the suspiciousindividual.

  "Mr. Francis Howard went on to see Mr. Ferdinand Knopf. This gentlemanwas having his warm bath, preparatory to going to bed. So Robertson toldthe detective. However, Mr. Knopf insisted on talking to Mr. Howardthrough his bath-room door. Mr. Knopf thanked him for all the trouble hewas taking, and felt sure that he and Mr. Shipman would soon recoverpossession of their diamonds, thanks to the persevering detective.

  "He! he! he!" laughed the man in the corner. "Poor Mr. Howard. Hepersevered--but got no farther; no, nor anyone else, for that matter.Even I might not be able to convict the thieves if I told all I knew tothe police.

  "Now, follow my reasoning, point by point," he added eagerly.

  "Who knew of the presence of the diamonds in the house of Mr. Shipmanand Mr. Knopf? Firstly," he said, putting up an ugly claw-like finger,"Mr. Shipman, then Mr. Knopf, then, presumably, the man Robertson."

  "And the tramp?" said Polly.

  "Leave the tramp alone for the present since he has vanished, and takepoint number two. Mr. Shipman was drugged. That was pretty obvious; noman under ordinary circumstances would, without waking, have his keysabstracted and then replaced at his own bedside. Mr. Howard suggestedthat the thief was armed with some anaesthetic; but how did the thiefget into Mr. Shipman's room without waking him from his natural sleep?Is it not simpler to suppose that the thief had taken the precaution todrug the jeweller _before_ the latter went to bed?"

  "But--"

  "Wait a moment, and take point number three. Though there was everyproof that Mr. Shipman had been in possession of L25,000 worth of goodssince Mr. Knopf had a cheque from him for that amount, there was noproof that in Mr. Knopf's house there was even an odd stone worth asovereign.

  "And then again," went on the scarecrow, getting more and more excited,"did it ever strike you, or anybody else, that at _no_ time, while thetramp was in custody, while all that searching examination was beinggone on with, no one ever saw Mr. Knopf and his man Robertson togetherat the same time?

  "Ah!" he continued, whilst suddenly the young girl seemed to see thewhole thing as in a vision, "they did not forget a single detail--followthem with me, point by point. Two cunning scoundrels--geniuses theyshould be called--well provided with some ill-gotten funds--butdetermined on a grand _coup_. They play at respectability, for sixmonths, say. One is the master, the other the servant; they take a housein the same street as their intended victim, make friends with him,accomplish one or two creditable but very small business transactions,always drawing on the reserve funds, which might even have amounted to afew hundreds--and a bit of credit.

  "Then the Brazilian diamonds, and the Parisians--which, remember, wereso perfect that they required chemical testing to be detected. TheParisian stones are sold--not in business, of course--in the evening,after dinner and a good deal of wine. Mr. Knopf's Brazilians werebeautiful; perfect! Mr. Knopf was a well-known diamond merchant.

  "Mr. Shipman bought--but with the morning would have come sober sense,the cheque stopped before it could have been presented, the swindlercaught. No! those exquisite Parisians were never intended to rest in Mr.Shipman's safe until the morning. That last bottle of '48 port, with theaid of a powerful soporific, ensured that Mr. Shipman would sleepundisturbed during the night.

  "Ah! remember all the details, they were so admirable! the letter postedin Brighton by the cunning rogue to himself, the smashed desk, thebroken pane of glass in his own house. The man Robertson on the watch,while Knopf himself in ragged clothing found his way into No. 26. IfConstable D 21 had not appeared upon the scene that exciting comedy inthe early morning would not have been enacted. As it was, in thesupposed fight, Mr. Shipman's diamonds passed from the hands of thetramp into those of his accomplice.

  "Then, later on, Robertson, ill in bed, while his master was supposed tohave returned--by the way, it never struck anybody that no one saw Mr.Knopf come home, though he surely would have driven up in a cab. Thenthe double part played by one man for the next two days. It certainlynever struck either the police or the inspector. Remember they only sawRobertson when in bed with a streaming cold. But Knopf had to be got outof gaol as soon as possible; the dual _role_ could not have been kept upfor long. Hence the story of the diamonds found in the garden of No. 22.The cunning rogues guessed that the usual plan would be acted upon, andthe suspected thief allowed to visit the scene where his hoard layhidden.

  "It had all been foreseen, and Robertson must have been constantly onthe watch. The tramp stopped, mind you, in Phillimore Terrace for somemoments, lighting a pipe. The accomplice, then, was fully on the alert;he slipped the bolts of the back garden gate. Five minutes later Knopfwas in the house, in a hot bath, getting rid of the disguise of ourfriend the tramp. Remember that again here the detective did notactually see him.

  "The next morning Mr. Knopf, black hair and beard and all, was himselfagain. The whole trick lay in one simple art, which those two cunningrascals knew to absolute perfection, the art of impersonating oneanother.

  "They are brothers, presumably--twin brothers, I should say."

  "But Mr. Knopf--" suggested Polly.

  "Well, look in the Trades' Directory; you will see F. Knopf & Co.,diamond merchants, of some City address. Ask about the firm among thetrade; you will hear that it is firmly established on a sound financialbasis. He! he! he! and it deserves to be," added the man in the corner,as, calling for the waitress, he received his ticket, and taking up hisshabby hat, took himself and his bit of string rapidly out of the room.