"But you said yourself that Felix never came to the inn on that night," he objected.
"So I thought, but it appears that I was mistaken. Fundy, the livery-stable keeper, told me that. Felix hired a horse from him on the 10th and 11th of June. On both occasions he did not return till midnight. Now, Francis was murdered on the 10th, and his corpse disappeared on the 11th. Felix is therefore responsible for both the murder and the concealment of the body."
"That is purely circumstantial evidence."
I laid down the arrowhead on the table.
"This is proof positive," I said triumphantly. "With that piece of flint Francis was killed."
"Really?" said Merrick skeptically, picking up the arrowhead. "With such a clumsy instrument he must have bungled the job considerably."
"Not at all. That arrowhead is steeped in virulent poison."
"The deuce!" cried Merrick, dropping it hastily. "Why did you not warn me of its danger? I might have cut myself and gone the same way as poor Francis Briarfield. How do you know the murder was so executed?"
"I told you about the discolored wound in the palm of the right hand?"
Merrick nodded.