“I am sure of it,” said Poirot politely. “You will permit a few questions, on your nephew’s behalf? About this lock, who ordered it from Hubbs’s?”

“I ordered it myself,” said Mr. Shaw. “I would not trust to any clerk in the matter. As to the keys, Mr. Ridgeway had one, and the other two are held by my colleague and myself.”

“And no clerk has had access to them?”

Mr. Shaw turned inquiringly to Mr. Vavasour. “I think I am correct in saying that they have remained in the safe where we placed them on the 23rd,” said Mr. Vavasour. “My colleague was unfortunately taken ill a fortnight ago⁠—in fact on the very day that Philip left us. He has only just recovered.”