certain that his plan was concerted down to the
smallest detail. Knowing that Sauverand was in love with his wife,
watching Sauverand's movements, he must obviously have noticed that his
detested rival used to pass under the windows of the house every
Wednesday and that Marie Fauville would go to her window.

"This is a fact of the first importance, one which was exceedingly
valuable to me; and it will impress you as being equal to a material
proof. Every Wednesday evening, I repeat, Sauverand used to wander round
the house. Now note this: first, the crime prepared by M. Fauville was
committed on a Wednesday evening; secondly, it was at her husband's
express request that Mme. Fauville went out that evening to go to the
opera and to Mme. d'Ersinger's."

Don Luis stopped for a few seconds and then continued:

"Consequently, on the morning of that Wednesday, everything was ready,
the fatal clock was wound up, the incriminating machinery was working to
perfection, and the proofs to come would confirm the immediate proofs
which M. Fauville held in reserve. Better still, Monsieur le Prefet, you
had received from him a letter in which he told you of the plot hatched
against him, and he implored your assistance for the morning of the next
day--that is to say, _after his death_!

"Everything, in short, led him to think that things would go according to
the 'hater's' wishes, when something occurred that nearly upset his
schemes: the appearance of Inspector Verot, who had been sent by you,
Monsieur le Prefet, to collect particulars about the Mornington heirs.
What happened between the two men? Probably no one will ever know. Both
are dead; and their secret will not come to life again. But we can at
least say for certain that Inspector Verot was here and took away with
him the cake of chocolate on which the teeth of the tiger were seen for
the first time, and also that Inspector Verot succeeded, thanks to
circumstances with which we are unacquainted, in discovering M.
Fauville's projects."

"This we know," explained Don Luis, "because Inspector Verot said so in
his own agonizing words; because it was through him that we learned that
the crime was to take place on the following night; and because he had
set down his discoveries in a letter which was stolen from him.

"And Fauville knew it also, because, to get rid of the formidable enemy
who was thwarting his designs, he poisoned him; because, when the poison
was slow in actin