“How did you guess that?”

“Quite easily. Through private information, I knew that fact when I came here on the evening of 22 June⁠—”

“After you left me⁠—”

“Yes, after turning the subject of our conversation to stories of crime and robbery which were sure to reduce you to such a nervous condition that you would not leave your bed, but would allow me to complete my search uninterrupted.”

“The scheme worked perfectly.”

“Well, I knew when I came here that there was a casket concealed in a safe with a secret lock, and that the seven-of-hearts was the key to that lock. I had merely to place the card upon the spot that was obviously intended for it. An hour’s examination showed me where the spot was.”

“One hour!”