The herbalist rose, walked to the bench at the far end of the room, and pointed to an object wrapped loosely in paper. Hanslet and Whyland followed him, and the former unwrapped the paper carefully. As the object appeared, they both uttered a startled exclamation. It was the blade of a knife, and with it a long wooden handle, with a hole running the whole of its length, and fitted with a setscrew.

Whyland bent over it with a look of triumph. “I knew it, all along!” he exclaimed. “Look at this blade! It is exactly similar to the ones found in the bodies of Tovey and Pargent. You see the dodge, don’t you? This blade just fits the hole in the handle. It’s meant to be pushed through and gripped by the setscrew. But, if you tighten the screw as far as it will go first, then put the blade in, it is held lightly, just by its very end. Now, if you stab a man with the blade fixed like that, what happens? The blade goes in all right, and there it stays, while you walk away with the handle. It’s beautifully simple, and you leave no fingermarks behind you.”