s pocket a small box, and taking out a piece
of paper, he took from it a button to which adhered a piece of navy blue
stuff.

Valerius, who was not in the least moved by the threat of the
commissioner, for he was a man to brave martyrdom, looked at the box
curiously. When the agent displayed the button, a movement of great
surprise escaped him.

"You see," the agent exclaimed, "that you know this cloth!"

"Will you permit me to look at it?" Valerius asked.

"Willingly, but on condition that you do not touch it; it is precious."

Valerius took the box, and approaching the front of the shop, looked at
the button and the piece of cloth.

"It is a button marked 'A.P.,' as you see, and we know that you use these
buttons."

"I do not deny it; they are good buttons, and I give only good things to
my customers."

Returning the box to the agent, he took a large book and began to turn
over the leaves; pieces of cloth were pasted on the pages, and at the
side were several lines of large handwriting. Arriving at a page where
was a piece of blue cloth, he took the box and compared this piece with
that of the button, examining it by daylight.

"Sir," he said, "I am going to tell you some very serious things."

"I am listening."

"We hold the assassin of the Rue Sainte-Anne, and it is I who will give
you the means of discovering him."

"You have made trousers of this cloth?"

"I have made three pairs; but there is only one pair that can interest
you, that of the assassin. I have just told you that the secrets of the
profession prevented me from replying to your questions, but what I have
just seen frees my conscience. As I explained to you, when I make a pair
of good trousers for a customer who pays me in good money, I do not think
I have the right to reveal the affairs of my client to any one in the
world, even to the law."

"I understand," interrupted the agent, whose impatience increased.

"But this reserve on my part rests on reciprocity: to a good customer, a
good tailor. If the customer is not good the reciprocity ceases, or,
rather, it continues on another footing--that of war; if any one treats
me badly, I return the same. The trousers to which this stuff
belongs"--he showed the button--"I made for an individual whom I do not
know, and who presented himself to me as an Alsacian, which I believed so
much more easily, because he spoke with a strong foreign accent. These
trousers--I need not tell you how carefu