If you will remember, he told us then that the cane had been given him in London.

Why did we not immediately say to ourselves: 'Fred is lying.

He could not have had this cane in London.

He was not in London.

He bought it in Paris'?
Then you found out, on inquiry at Cassette's, that the cane had been bought by a person dressed very like Robert Darzac, though, as we learned later, from Darzac himself, it was not he who had made the purchase.