“See that?” he said. “That’s the end of a fine hypodermic needle. I’m beginning to see what happened, now. He was injected with some powerful toxic agent by means of a hypodermic syringe, the needle of which broke off in the process. The nature of the poison we shall be able to determine by an examination of this fragment. But I don’t understand that white incrustation. Let me have another look at it.”

He selected a small phial from his case, put the fragment of the needle into it, and labelled it. Then he turned once more to Mr. Copperdock’s body, and examined the patch once more with a lens. Finally he removed some of the white powder and put it in another phial, which he also sealed and labelled.

Then he beckoned Whyland aside, and the two conversed for a moment in low whispers.