"Against the Hindus, on the other hand, practically the only basis for suspicion is that such a crime might be temperamentally possible to them. They may have been on the ground, and the method of the murder savours strongly of Thuggee—though don't forget that Swain admitted he could have tied that knot. Besides, if it was the Thug who followed them, he wouldn't have made any noise, and most certainly he couldn't have left the prints of Swain's fingers on the body. But if Swain is right in his assertion that he saw the snake in the arbour, it is probable that the Thug wasn't far away.
"Against an unknown it may be urged that neither Swain nor the Hindus could have committed the crime; but I don't see how an unknown could either, unless he happened to be one of the three or four people in the world with finger-tips like Swain's. And that is too far-fetched to be believable.
"But this I am sure of, Lester," and Godfrey leaned forward again: "the murder was committed either by Swain or by someone anxious to implicate Swain. We agree that it wasn't Swain. Very well, then: the person who committed the murder made a noise in following Miss Vaughan and her father so that she should think it was Swain who was following them; he picked up the blood-stained handkerchief, which Swain had dropped perhaps when he fled from the arbour, and placed it beside the body; and in some way inconceivable to me he pressed the prints of Swain's fingers on the dead man's robe. Now, to do that, he must have known that Swain was injured—the blood-stained handkerchief would tell him that; but he must also have known that it was his right hand that was injured. There was no blood on Swain's left hand."
Again Godfrey paused. I was following his reasoning with such absorbed attention that I could feel my brain crinkle with the effort.
"Now, listen," said Godfrey, and I could have smiled at the uselessness of the admonition—as if I were not already listening with all my faculties! "There is only one way in which the murderer could have known that it was Swain's right hand, and that was by overhearing the conversation in the arbour. But if he overheard that much, he overheard it all, and he knew therefore what it was Swain proposed to do. He knew that Vaughan's sanity was to be questioned; he knew that he would probably be placed in a sanitarium; he knew that Miss Vaughan would probably marry Swain. Presuming that it was Silva, he knew that, unless something was done to stop it, a very few days would place both Vaughan and his daughter beyond his reach."
"That is true," I admitted; "but Vaughan was beyond his reach a good deal more certainly dead than he would have been in a sanitarium. Besides, it isn't at all certain that he would have been sent to a sanitarium."
"That's an objection, surely," Godfrey agreed; "but I must find out if Vaughan is really beyond his reach dead."
I stared at him.
"You don't mean...."
"I don't know what I mean, Lester. I can feel a sort of dim meaning at the back of my mind, but I can't get it out into the light."