This button belonged to Florentin."

"To your brother?"

"Yes, to Florentin, who, the day of the crime, had been to see Caffie."

"That is true; the concierge told the commissioner of police that he
called about three o'clock."

Phillis gave a cry of despair.

"They know he was there? Then it is more serious than we imagined or
believed."

"In answering a question as to whom Caffie had received that day, the
concierge named your brother. But as this visit took place between three
and half-past, and the crime was certainly committed between five and
half-past, no one can accuse your brother of being the assassin, since
he left before Caffie lighted his lamp. As this lamp could not light
itself, it proves that he could not have butchered a man who was living
an hour after the concierge saw your brother and talked with him."

"What you say is a great relief; if you could know how alarmed we have
been!"

"You were too hasty to alarm yourself."

"Too hasty? But when Florentin read the account to us and came to the
button, he exclaimed, 'This button is mine!' and we experienced a
shock that made us lose our heads. We saw the police falling on us,
questioning Florentin, reproaching him with the past, which would be
retailed in all the newspapers, and you must understand how we felt."

"But cannot your brother explain how he lost this button at Caffie's?"

"Certainly, and in the most natural way. He went to see Caffie, to ask
him for a letter of recommendation, saying that he had been his clerk
for several years. Caffie gave it to him, and then, in the course of
conversation, Caffie spoke of a bundle of papers that he could not find.
Florentin had had charge of these papers, and had placed them on a high
shelf in the closet. As Caffie could not find them, and wanted them,
Florentin brought a small ladder, and, mounting it, found them. He was
about to descend the ladder, when he made a misstep, and in trying to
save himself, one of the buttons of his trousers was pulled off."

"And he did not pick it up?"

"He did not even notice it at first. But later, in the street, seeing
one leg of his trousers longer than the other, he thought of the ladder,
and found that he had lost a button. He would not return to Caffie's to
look for it, of course."

"Of course."

"How could he foresee that Caffie would be assassinated? That the crime
would be so skilfully planned and executed that the criminal would
escape? That two