“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!”
“Observe the fellow in mosaic.”
“The old emperor?”
“That old emperor is an exact representation of the king of hearts on all playing cards.”
“That’s right. But how does the seven of hearts open the larger safe at one time and the smaller safe at another time? And why did you open only the larger safe in the first instance? I mean on the night of 22 June.”