"Of course, this night's adventure was never allowed to get into the papers," added the man in the corner with his mild smile. "Had the plan been successful, we should have heard all about it, with a long eulogistic article as to the astuteness of our police; but as it was--well, the tramp sauntered up the mews--and--there he remained for aught Mr. Francis Howard or the other constables could ever explain. The earth or the shadows swallowed him up. No one saw him climb one of the garden walls, no one heard him break open a door; he had retreated within the shadow of the garden walls, and was seen or heard of no more." "One of the servants in the Phillimore Terrace houses must have belonged to the gang," said Polly with quick decision. "Ah, yes! but which?" said the man in the corner, making a beautiful knot in his bit of string. "I can assure you that the police left not a stone unturned once more to catch sight of that tramp whom they had had in custody for two days, but not a trace of him could they find, nor of the diamonds, from that day to this." 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 the front, 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 giving them whiskies-and-sodas before saying good night. The servants had just finished washing up, and were waiting to go to bed; neither they nor Mr. Shipman nor his guests had seen or heard anything of the suspicious individual. "Mr. Francis Howard went on to see Mr. Ferdinand Knopf. This gentleman was having his warm bath, preparatory to going to bed. So Robertson told the detective. However, Mr. Knopf insisted on talking to Mr. Howard through his bath-room door. Mr. Knopf thanked him for all the trouble he was taking, and felt sure that he and Mr. Shipman would soon recover possession of their diamonds, thanks to the persevering detective. "He! he! he!" laughed the man in the corner. "Poor Mr. Howard. He persevered--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 to the police. "Now, follow my reasoning, point by point," he added eagerly. "Who knew of the presence of the diamonds in the house of Mr. Shipman and 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.