As I was returning homeward in the evening by way of Mitre Court, I overtook Mr. Marchmont, who was also bound for our chambers, and we walked on together.
"I had a note from Thorndyke," he explained, "asking for a specimen of handwriting, so I thought I would bring it along myself, and hear if he has any news."
When we entered the chambers, we found Thorndyke in earnest consultation with Polton, and on the table before them I observed, to my great surprise, the dagger with which the murder had been committed.
THE ALUMINIUM DAGGER.
"I have got you the specimen that you asked for," said Marchmont. "I didn't think I should be able to, but, by a lucky chance, Curtis kept the only letter he ever received from the party in question."
He drew the letter from his wallet, and handed it to Thorndyke, who looked at it attentively and with evident satisfaction.
"By the way," said Marchmont, taking up the dagger, "I thought the inspector took this away with him."
"He took the original," replied Thorndyke. "This is a duplicate, which Polton has made, for experimental purposes, from my drawings."
"Really!" exclaimed Marchmont, with a glance of respectful admiration at Polton; "it is a perfect replica—and you have made it so quickly, too."