operation. "Just the amount of dirt the soles of one's boots would be likely to collect if one came with wet feet along the muddy platform of the station."
"Yes; but, my dear chap, that might easily have happened—particularly on such a day as this has been—before Lord Stavornell's arrival. He can't have been the only person to enter this compartment since morning."
"Granted. But he is supposed to have been the only person who entered it after it was swept, Mr. Narkom; and that, as I told you, was done by his orders immediately before the train started. We've got past the point of 'guesswork' now. We've established the presence of the second party beyond all question. We also know that he was a person with whom Stavornell felt at ease, and was intimate enough with to feel no necessity for putting himself out by entertaining with those little courtesies one is naturally obliged to show a guest."
"How do you make that out?"
"This newspaper. He was reading at the time he was shot. You can see for yourself where the bullet went through—this hole here close to the top of the paper. When a man invites another man to occupy with him a compartment which he has engaged for his own exclusive use—and this Stavornell must have done, otherwise the man couldn't have been travelling with him—and then proceeds to read the news instead of troubling himself to treat his companion as a guest, it is pretty safe to say that they are acquaintances of long standing, and upon such terms of intimacy that the social amenities may be dispensed with inoffensively. Now look at the position of this newspaper lying between the dead man's feet. Curved round the ankle and the lower part of the calf of the left leg. If we hadn't found the key we still should have known that the murderer got out on that side of the carriage."
"How should we have known?"
"Because a paper which has simply been dropped could not have assumed that position without the aid of a strong current of air. The opening of that door on the right-hand side of the body supplied that current, and supplied it with such strength and violence that the paper was, as one might say, absolutely sucked round the man's leg. That is a positive proof that the train was moving at the time it happened, for the day, as you know, has been windless.
"Now look! No powder on the face, no smell of it in the compartment; and yet the pistol found in his hand is an ordinary American-made thirty-eight calibre revolver. We have an amateur assassin to deal with, Mr. Narkom, not a hardened criminal; and the witlessness of the fellow is enough to bring the case to an end before this night is over. Why didn't he discharge that revolver to-day, and have enough sense to bring a thimbleful of powder to burn in this compartment after the work was done? One knows in an instant that the weapon used was an air-pistol, and that the fellow's only thought was how to do the thing without sound, not how to do it with sense. I don't suppose that there are three places in all London that stock air-pistols, and I don't suppose that they sell so many as two in a whole year's time. But if one has been sold or repaired at any of the shops in the past six months—well, Dollops will know that in less than no time. I 'phoned him to make inquiries. His task's an easy one, and I've no doubt he will bring back the word I want in short order. And now, Mr. Narkom, as our friend the assassin is such a blundering, short-sighted individual, it's just possible that, forgetting so many other important things, he may have neglected to search the body of his victim. Let us do it for him."
As he spoke he bent over the dead man and commenced to search the clothing. He slid his hand into the inner