. 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."

"Why? Because I always placed the seven of hearts in the same way. I
never changed the position. But, yesterday, I observed that by reversing
the card, by turning it upside down, the arrangement of the seven spots
on the mosaic was changed."

"Parbleu!"

"Of course, parbleu! But a person has to think of those things."

"There is something else: you did not know the history of those letters
until Madame Andermatt---"

"Spoke of them before me? No. Because I found in the safe, besides
the casket, nothing but the correspondence of the two brothers which
disclosed their treachery in regard to the plans."

"Then it was by chance that you were led, first, to investigate the
history of the two brothers, and then to search for the plans and
documents relating to the sub-marine?"

"Simply by chance."

"For what purpose did you make the search?"

"Mon Dieu!" exclaimed Daspry, laughing, "how deeply interested you are!"

"The subject fascinates me."

"Very well, presently, after I have escorted Madame Andermatt to a
carriage, and dispatched a short story to the `Echo de France,' I will
return and tell you all about it."

He sat down and wrote one of those short, clear-cut articles which
served to amuse and mystify the public. Who does not recall the
sensation that followed that article produced throughout the entire
world?

"Arsene Lupin has solved the problem recently submi