“Well, I apologize. But you will be glad to hear that the experiment succeeded. Somebody did come into your room last night, Reeves, and wandered all over it, though of course he found nothing that was of the slightest interest to him, because there was nothing to find.” “And how do you know all this?” “That is where the chewing-gum comes in. Seccotine would have done: but chewing-gum is more certain. I do not profess to understand why people chew: my impression is that it is merely a kind of fidgeting. Those people who talk about the unconscious would probably tell you that all fidgeting is a form of ‘compensation.’ Observe that word, for it is the great hole in their logic. Their idea is that So-and-so does not murder his grandmother, but he does twiddle his thumbs. They will tell you, consequently, that twiddling your thumbs is a kind of compensation for not murdering your grandmother. But the whole strength of their case should rest on their ability to _prove_ a connexion between the two things, and instead of proving it you will find that they steadily assume it. However, as I was saying—the peculiarity of van Beuren’s special chewing-gum is this: that it can be drawn out to an almost indefinite length, and forms a thread of almost invisible fineness. If you stretch such threads, say, between one chair and another all over a room, as I did round your room, Reeves, last night, the great probability is that a casual visitor will walk into it and carry whole strands of it away with him, without noticing anything peculiar.” “What!” said Reeves, “you mean like Sherlock Holmes and the cigarette-ash on the carpet?” “It was not one of Holmes’ more original performances. He had been anticipated, in point of fact, by the prophet Daniel. You should read the story of Bel and the Dragon, Reeves.” “And now,” said Gordon, “I suppose we proceed to the station, and take a good look at the trouser-ends of all our club-fellows as they wait for the London train?” “Why, no. I do not think that method would be very fruitful. My idea was not to discover _who_ it is that visits Reeves’ room, but to make sure that there is somebody who does so, and that he does not come through the door.” “In fact, that he comes through the window?” “No, my dear Gordon, it is not everybody who has your agility in negotiating windows. The windows in question are a good twenty feet from the ground; there is no drain-pipe near them; and anyone who attempted to put a ladder up to them would leave traces among the begonias beneath which even a caddy would not find it difficult to follow up.” “Well, come on, don’t be so mysterious. What is it? A secret passage?” “That seems to be the only sensible solution. One does not, of course, expect a secret passage in a club-house. But then, you see, this is not like other club-houses, and you, Reeves, must have been struck like myself by the significance of what Marryatt was saying last night.” “What was Marryatt saying last night?”