it is time for you
to vacate your position. I must appoint a new minister of police."

"Sire," replied the minister, "how much time will you give me to
discover the assassin?"

"One week," replied the emperor.

"I thank your majesty," replied the minister, bowing. "In one week,
you shall have the assassin's head, or my resignation."

"Good," said the emperor; "and to stimulate the activity of your
people, I hereby authorize you to offer a reward of twenty thousand
francs, for the detection of the assassin of the Rue La Harpe, the Rue
Richelieu, and the Boulevard, if it prove, as I imagine, that one
individual perpetrated these crimes, or five thousand francs each, if
there were three criminals. Good day, Mr. Fouche; let me have a report
of your doings without delay."

The secret of Mr. Fouche's confident promise to detect the assassin
was the reliance he placed in the activity, daring, and intelligence
of Pierre Lacour. He sent for him, and related his conversation with
the emperor, enlarging on the munificent reward promised by Napoleon.

"I am poor," said Lacour, "but higher motives than hopes of reward
stimulate me to perform this duty. Yet, should I be successful, a sum
of money like this would enable me to wed one, who, though I
voluntarily offered to release her from her engagement has loved me as
well in my misfortunes as in happier times. In one week, therefore,
Mr. Fouche, I will enable you to redeem your pledge to the emperor."

Four days passed away, and yet the minister of police heard nothing
from Lacour. But the young man had not been inactive; and once or
twice he had obtained, what he considered, traces of the person
calling himself Belmont, the supposed assassin of the Rue la Harpe,
and, by presumption, of the other murders; but these traces led to no
result.

Whether in search of diversion, or that a vague hope whispered to him
that he might obtain some intelligence by so doing, Lacour, on the
fifth night after his interview with the minister, went to a masked
ball at the grand opera house, in the costume of an officer of the
Fusilier Guard, which chance led him to select. Weary of the noise and
confusion, sad and discouraged, he had withdrawn from the crowded
circle of dancers, when some one touched him on the shoulder.

"Captain Lassalle," said a sweet musical voice, "you are known, though
the uniform you wear is not that of your own corps."

Lacour turned with the intention of correctin