As the inspector’s footsteps died away on the stairs, we looked at one another and smiled.

“That was a fine peroration, even for Blandy,” I remarked. “But haven’t you rather misled the poor man? He is evidently under the delusion that he has harnessed you firmly to his chariot.”

“I only promised to look over his salvage; which I am quite ready to do for my own satisfaction.”

“I don’t quite see why. You are not likely to learn anything from it; and even if you were, this affair is not our concern.”

“I don’t know that we can say that,” he replied. “But we needn’t argue the point. I don’t mind admitting that mere professional curiosity is a sufficient motive to induce me to keep an eye on the case.”

“Well, that would be good news for Blandy, for it is obvious that he is completely stumped; and so am I, for that matter, assuming that there is anything abnormal about the case. I don’t feel convinced that there is.”

“Exactly,” said Thorndyke; “that is Blandy’s difficulty. It is a very odd and puzzling case. Taking the group of circumstances as a whole, it seems impossible to accept it as perfectly normal; but yet, when one examines the factors separately, there is not one of them at which one can cavil.”

“I am not sure that I follow that,” said I. “Why can we not accept the circumstances as normal? I should like to hear you state the case as it presents itself to you.”

“Well,” he replied, “let us first take the facts as a whole. Here is a house which, in some unknown way, catches fire in the small hours of the morning. In the debris of that house is found the body of a man who has apparently been burned to death.”

“Yes,” I agreed, with a grin, “the body certainly had that appearance.”

“It transpires later,” Thorndyke continued, disregarding my comment, “that the death of that man, A, benefits another man, B, to the extent of four thousand pounds. But the premises in which the fire occurred belong to and are controlled by B; and they had been lent by B to A for his occupation while B should be absent in Ireland. The event by which the benefit accrues to B— the death of Harold Moxdale — has occurred quite a short time after the fire. Finally, the tenant, B, who had ostensibly gone away from his residence to make a short visit to Ireland, has never returned to that residence or made any communication to his landlord — has, in fact, disappeared.”

“Blandy doesn’t admit Haire has disappeared,” I objected

“We mustn’t take Blandy’s statements too literally. In spite of his disclaimers, it is evident that he is hot on the trail of Mr. Gustavus Haire; and the fact is that, in the ordinary sense of the word, Haire has disappeared. He has absented himself from his ordinary places of resort, he has communicated with nobody, and he has left no traces by which the police could discover his whereabouts.

But now take the facts separately. The origin of the fire is a mystery, but there is not a particle of evidence of incendiarism. The only person who could have been suspected had been overseas several days before the fire broke out.”

“Do you consider that his absence at the time puts him quite outside the picture? I mean, don’t you think that the fire could have been started by some sort of timing apparatus?”

“Theoretically, I have no doubt that it could. But it would have had to be a rather elaborate apparatus. The common alarm clock would not have served. But really the question seems to be of only academic interest for two reasons. First, the fire experts were on the look-out for some fire-raising appliance and found no trace of any; second, the presence of Moxdale in the rooms seems to exclude the possibility of any such appliance having been used, and, third, even the appliance that you are postulating would not have served its purpose with anything like calculable certainty.”

“You mean that it might not have worked, after all?”

“No. What I mean is that it could not have been adjusted to the actual purpose, which would have been to cause the death of the man. It would have been useless to fire the house unless it were certain that the man would be in it at the time and that he would not be able to escape. But neither of these things could be foreseen with any degree of certainty. No, Jervis, I think that, on our present knowledge, we must agree with Blandy and the others that no suspicion of arson stands against Gustavus Haire.”

“That is what he says, but it is obvious that he does suspect Haire.”

“I was speaking in terms of evidence,” Thorndyke rejoined. “Blandy admits that he has nothing against Haire and therefore cannot treat the disappearance as a flight. If he met Haire, he couldn’t detain him or charge him with any unlawful act. But he feels — and I think quite rightly — that Haire’s disappearance is a mystery that needs to be explained. Blandy, in fact, is impressed by the case as a whole; by the appearance of a connected series of events with the suggestion of a purpose behind it. He won’t accept those events as normal events, brought about merely by chance, but he sees no way of challenging them so as to start an inquiry. That is why he came to us. He hopes that we may be able to give him some kind of leading fact.”

“And so you are proposing to go over the box of rubbish that he has brought on the chance that you may find the leading fact among it?”

“I think we may as well look over it,” he replied. “It is wildly improbable that it will yield any in formation, but you never know. We have, on more than one occasion, picked up a useful hint from a most unlikely source. Shall we go up and see what sort of rubbish the box contains?”

We ascended to the laboratory floor, where we found Polton looking with undissembled distaste at a large packing-case filled to the brim with miscellaneous oddments, mostly metallic, and all covered with a coating of white ash.

“Looks as if Mr. Blandy has turned out a dust bin,” Polton commented, “and passed the contents on to us. A rare job it was getting it up the stairs. Shall I put the whole of the stuff out on the bench?”

“You may as well,” replied Thorndyke, “though I think Blandy might have weeded some of it out. Door-handles and hinges are not likely to yield much information.”

Accordingly, we all set to work transferring the salvage to the large bench, which Polton had tidily covered with newspaper, sorting it out to some extent as we did so, and making a preliminary inspection. But it was a hopeless-looking collection, for the little information that it conveyed we possessed already. We knew about the tools from the little workshop, the projectors and the remains of gramophones and kinematograph cameras, and, as to the buttons, studs, keys, pen-knives, and other small personal objects, they were quite characterless and could tell us nothing.

Nevertheless, Thorndyke glanced at each item as he picked it out of its dusty bed and laid it in its appointed place on the bench, and even Polton began presently to develop an interest in the proceedings. But it was evidently a merely professional interest, concerning itself exclusively with the detached fragments of the gramophone motors and other mechanical remains and particularly with the battered carcase of the grandfather clock, and I strongly suspected that he was simply on the look-out for usable bits of scrap. Voicing my suspicion, I suggested:

“This ought to be quite a little windfall for you, Polton. A lot of this clockwork seems to be quite sound — I mean as to the separate parts.”

He laid down the clock (as tenderly as if it had been in going order) and regarded me with a cunning and crinkly smile.

“It’s an ill wind, sir, that blows nobody good. My reserve stock of gear-wheels and barrels and other spare parts will be all the richer for Mr. Blandy’s salvage. And you can’t have too many spares; you never know when one of them may be the very one that you want. But might I suggest that, as this is a rather dirty job, you let me finish setting the things out and come and look over them at your leisure in the morning, when I have been through them with a dusting-brush.”

As I found the business not only dirty but rather boresome — and in my private opinion perfectly futile — I caught at the suggestion readily, and Thorndyke and I then retired to the sitting-room to resume our operations on the test-slides, after cleansing our hands.

“We seem to have been ejected,” I remarked as we sat down to the table. “Perhaps our presence hindered the collection of scrap.”

Thorndyke smiled. “That is possible,” said he. “But I thought that I detected an awakening interest in the inspection. At any rate, it will be as well to let him sort out the oddments before we go through them. He is a good observer, and he might notice things that we should overlook and draw our attention to them.”

“You don’t really expect to get any information out of that stuff, do you?” I asked.

“No,” he replied. “The inspection is little more than a formality, principally to satisfy Blandy. Still, Jervis, we have our principles, and one of them — and a very important one — is to examine everything, no matter how insignificant. This won’t be the first rubbish-heap that we have inspected; and it may be that we shall learn something from it, after all.”

Thorndyke’s suggestion of “an awakening interest” on Polton’s part was curiously confirmed on the following day and thereafter. For, whereas I made my perfunctory inspection of the rubbish and forthwith — literally — washed my hands of it, and even Thorndyke looked it over with little enthusiasm, Polton seemed to give it a quite extraordinary amount of attention. By degrees, he got all the mechanical oddments sorted out into classified heaps, and once I found him with a small sieve, carefully sifting the ash and dirt from the bottom of the box. And his interest was not confined to the contents of that unclean receptacle; for, having been shown the gold watch which the inspector had left with us, he skilfully prised it open and examined its interior through his eyeglass with the most intense concentration.

Moreover, I began to notice something new and unusual in his manner and appearance: a suggestion of suppressed excitement and a something secret and conspiratorial in his bearing. I mentioned the matter to Thorndyke, but, needless to say, he had noticed it and was waiting calmly for the explanation to transpire. We both suspected that Polton had made some sort of discovery, and we both felt some surprise that he had not communicated it at once.

And then, at last, came the disclosure; and a most astonishing one it was. It occurred a few mornings after Blandy’s visit, when Thorndyke and I, happening to go up together to the laboratory, found our friend at the bench, poring over one of the heaps of mechanical fragments with a pair of watchmaker’s tweezers in his hand.

“Well, Polton,” I remarked, “I should think that you have squeezed the inspector’s treasures nearly dry.”

He looked up at me with his queer, crinkly smile and replied: “I am rather afraid that I have, sir.”

“And now, I suppose, you know all about it?”

“I wouldn’t say that, sir, but I know a good deal more than when I started. But I don’t know all that I want to know.”

“Well,” I said, “at any rate, you can tell us who set fire to that house.”

“Yes, sir,” he replied, “I think I can tell you that, without being too positive.”

I stared at him in astonishment, and so did Thorndyke. For Polton was no jester, and, in any case, was much too well-mannered to let off jokes at his principals.

“Then,” said I, “tell us. Who do you say it was?”

“I say that it was Mr. Haire,” he replied with quiet conviction.

“But, my dear Polton,” I exclaimed. “Mr. Haire was in Dublin when the fire broke out, and had been there five days. You heard the inspector say that it was impossible to suspect him.”

“It isn’t impossible for me,” said Polton. “He could have done it quite well if he had the necessary means. And I am pretty sure that he had the means.”

“What means had he?” I demanded.<............