Finchley. They get into Kingscote's garden and watch him let Campbell out. While he is gone, Challitt quietly steps through the French window into the smoking-room, and waits for him, Gillard remaining outside.

"Kingscote returns, and Challitt accuses him of taking the stones. Kingscote is contemptuous—doesn't care for Challitt, because he knows he is powerless, being the original thief himself; besides, knows there is no evidence, since the diamonds are sold and dispersed long ago. Challitt offers to divide the plunder with him—Kingscote laughs and tells him to go; probably threatens to throw him out, Challitt being the smaller man. Gillard, at the open window, hears this, steps in behind, and quietly knocks him on the head. The rest follows as a matter of course. They fasten the window and shutters, to exclude observation; turn over all the drawers, etc., in case the jewels are there; go to the best bedroom and try there, and so on. Failing (and possibly being disturbed after a few hours' search by the noise of the acquisitive gardener), Gillard, with the instinct of an old thief, determines they shan't go away with nothing, so empties Kingscote's pockets and takes his watch and chain and so on. They go out by the front door and shut it after them. Voilà tout."

I was filled with wonder at the prompt ingenuity of the man who in these few hours of hurried inquiry could piece together so accurately all the materials of an intricate and mysterious affair such as this; but more, I wondered where and how he had collected those materials.

"There is no doubt, Hewitt," I said, "that the accurate and minute application of what you are pleased to call your common sense has become something very like an instinct with you. What did you deduce from? You told me your conclusions from the examination of Ivy Cottage, but not how you arrived at them."

"They didn't leave me much material downstairs, did they? But in the bedroom, the two drawers which the thieves found locked were ransacked—opened probably with keys taken from the dead man. On the floor I saw a bent French nail; here it is. You see, it is twice bent at right angles, near the head and near the point, and there is the faint mark of the pliers that were used to bend it. It is a very usual burglars' tool, and handy in experienced hands to open ordinary drawer locks. Therefore, I knew that a professional burglar had been at work. He had probably fiddled at the drawers with the nail first, and then had thrown it down to try the dead man's keys.

"But I knew this professional burglar didn't come for a burglary, from several indications. There was no attempt to take plate, the first thing a burglar looks for. Valuable clocks were left on mantelpieces, and other things that usually go in an ordinary burglary were not disturbed. Notably, it was to be observed that no doors or windows were broken, or had been forcibly opened; therefore, it was plain that the thieves had come in by the French window of the smoking-room, the only entrance left open at the last thing. Therefore, they came in, or one did, knowing that Mr. Kingscote was up, and being quite willing—presumably anxious—to see him. Ordinary burglars would have waited till he had retired, and then could have got through the closed French window as easily almost as if it were open, notwithstanding the thin wooden shutters, which would never stop a burglar for more than five minutes. Being anxious to see him, they—or again, one of them—presumably knew him. That they had come to get something was plain, from the ransacking. As, in the end, they did steal his money, and watch, but did not take larger valuables, it was plain that they had no bag with them—which proves not only that they had not come to burgle, for every burglar takes his bag, but that the thing they came to get was not bulky. Still, they could easily have removed plate or clocks by rolling them up in a table-cover or other wrapper, but such a bundle, carried by well-dressed men, would attract attention—therefore it was probable that they were well dressed. Do I make it clear?"

"Quite—nothing seems simpler now it is explained—that's the way with difficult puzzles."

"There was nothing more to be got at the house. I had already in my mind the curious coincidence that the panels at Chelsea had been broken the very night before that of the murder, and determined to look at them in any case. I got from you the name of the man who had lived in the panelled room before Kingscote, and at once remembered it (although I said nothing about it) as that of the young man who had been chloroformed for his employer's diamonds. I keep things of that sort in my mind, you see—and, indeed, in my scrap-book. You told me yourself about his imprisonment, and there I was with what seemed now a hopeful case getting into a promising shape.

"You went on to prevent any setting to rights at Chelsea, and I made enquiries as to Challitt. I found he had been released only a few days before all this trouble arose, and I also found the name of another man who was released from the same establishment only a few days earlier. I knew this man (Gillard) well, and knew that nobody was a more likely rascal for such a crime as that at Finchley. On my way to Chelsea I called at my office, gave my clerk certain instructions, and looked up my scrap-book. I found the newspaper account of the chloroform business, and also a photograph of Gillard—I keep as many of these things as I can collect. What I did at Chelsea you know. I saw that one panel was of old wood and the rest new. I saw the hole in the old panel, and I asked one or two questions. The case was complete."

We proceeded with our dinner. Presently I said: "It all rests with the police now, of course?"

"Of course. I should think it very probable that Challitt and Gillard will be caught. Gillard, at any rate, is pretty well known. It will be rather hard on the surviving Kingscote, after engaging me, to have his dead brother's diamond transactions publicly exposed as a result, won't it? But it can't be helped. Fiat justitia, of course."

"How will the police feel over this?" I asked. "You've rather cut them out, eh?"

"Oh, the police are all right. They had not the information I had, you see; they knew nothing of the panel business. If Mrs. Lamb had gone to Scotland Yard instead of to the policeman on the beat, perhaps I should never have been sent for."

The same quality that caused Martin Hewitt to rank as mere "common-sense" his extraordinary power of almost instinctive deduction, kept his respect for the abilities of the police at perhaps a higher level than some might have considered justified.

We sat some little while over our dessert, talking as we sat, when there occurred one of those curious conjunctions of circumstances that we notice again and again in ordinary life, and forget as often, unless the importance of the occasion fixes the matter in the memory. A young man had entered the dining-room, and had taken his seat at a corner table near the back window. He had been sitting there for some little time before I particularly observed him. At last he happened to turn his thin, pale face in my direction, and our eyes met. It was Challitt—the man we had been talking of!

I sprang to my feet in some excitement.

"That's the man!" I cried. "Challitt!"

Hewitt rose at my words, and at first attempted to pull me back. Challitt, in guilty terror, saw that we were between him and the door, and turning, leaped upon the sill of the open window, and dropped out. There was a fearful crash of broken glass below, and everybody