"Ah! no, my dear fellow," he hastened to reassure me. "You quite misunderstand my meaning. I hold the theory that in life these people were friends of Patterson's, that's all." "What makes you suspect such a thing?" "Well, I watched our friend very closely this evening, and that's the conclusion I've arrived at." "You really think that he is concealing facts which might throw light on the affair?" I exclaimed, much surprised. "Yes," he answered, "I feel certain of it--absolutely certain." CHAPTER SIX. WHAT I SAW IN THE PARK. For a long time, sitting by the open window and looking out upon the starry night, we discussed the grim affair in all its details. The piano had stopped its tinkling, a dead silence had fallen upon the old-world square, one of the relics of bygone London, and the clock upon the hall had struck one o'clock with that solemnity which does not fail to impress even the most dissipated resident of Gray's. As a bachelor abode Gray's Inn is as comfortable and convenient a spot as there is in London, for there is always a quiet, restful air within; the grey, smoke-stained houses open on airy squares, and until a couple of years ago, quite a large colony of rooks made their home in the great old trees. It is an oasis of peace and repose in the very centre of that gigantic fevered city, where the whirl of daily life is unceasing, where in the east and south toiling millions struggle fiercely for their bread, while in the west is greater wealth and extravagance than in all the world besides. "I think," said Dick at last, after he had put forth one or two theories, "that if we manage to get to the bottom of this affair we shall discover some very startling facts." "That's absolutely certain," I answered. "The disappearance of the fair girl, and the substitution of the other, is in itself a fact absolutely unique in the annals of crime. Whoever effected that change must have been indeed a bold person." "Didn't the people next door see any taxi drive up, or notice anything being brought up to the house?" "No. That's the strangest part of it," I responded. "Nothing was seen of any cab or conveyance, although, of course, there must have been one." "And that inquiry by telephone was a remarkable incident," Dick went on. "You say that the inquirer was popping about to various call-rooms ringing up his confederates. That shows that there were two or three in the secret. It hardly seems feasible that the man who rang up from the Minories was the same as the one with whom you spoke at Putney." "No; but the arrangement to meet in St. James's Park to-morrow is extraordinary, to say the least."