"Most likely," responded the doctor. "A man to make experiments on an elaborate scale as he has must necessarily have been absorbed in them. Indeed, that apparatus must have taken a year to prepare, and no doubt he has been making constant trials for months. He probably intended to give forth his discovery to the world as a great surprise, but has been prevented from doing so by some extraordinary combination of circumstances which has resulted in his death." At that instant we heard a voice in the hall--a quick, sharp voice extremely familiar to me, but nevertheless it caused me to start. Next instant, however, there entered the room the well-known figure of Dick Cleugh. "Hulloa, old fellow!" he exclaimed, greeting me and taking me aside. "I thought I'd run down and see what's in this. Funny affair it seems, doesn't it?" "Yes," I answered. "A most remarkable mystery. But why have you come out here?" "Soon after you left I went to find Lily, but she's gone into the country. So having nothing else to do I came down to see what had occurred. I knew, of course, from Patterson's telegram, that it was something unusual." "Have you been upstairs?" "Yes, I've been worrying around this last half-hour, while you and Patterson have been making inquiries next door. I've been having a look about with the Doctor. It seems that there's some wonderful apparatus in the laboratory--a discovery for liquefying hydrogen. Has he told you about it?" "Yes," I responded. "What's your theory?" "By Jove! old fellow," he said smiling, "the whole affair is so devilish uncanny, with those snakes upstairs, water boiling without any heat beneath it, and one thing and another, that I'm utterly at a loss how to account for it all." "You think they've been murdered?" "Of course," answered the astute Cleugh. "But the doctor can't discover how. There is not a scratch upon them. The discovery of those flash notes on the man looks as though he were a bit of a swell swindler, doesn't it?" "Yes," I said. Then taking him across to the dining-table I explained how we had discovered the three cards concealed beneath the plates. He took the cards in his hand, turning them over, and examining them carefully. "Strange," he ejaculated. "This adds still another phase to the affair. It is really a most sensational discovery, and will work up well for to-morrow." "No, Mr. Cleugh," put in Patterson quickly, overhearing his remark, "I beg of you to publish nothing whatever about it until I give you permission. In this we are bound to preserve secrecy for the present in order that our inquiries may not be thwarted. Even the neighbours will remain in ignorance of the real nature of things, so carefully do I intend to guard against any public sensation. Whatever information I can give you I will do so willingly, in order that you can prepare your account of it, but remember that not a word must be published until I give you permission."