"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 careful I was with them. I am a patriot, sir. He agreed to pay for them on delivery. When they were delivered, the young apprentice who took them had the weakness to not insist upon the money. I went to him, but could obtain nothing; he would pay me the next day, and so on. Finally he disappeared, leaving no address." "And this customer?" "I will give you his name without the slightest hesitation. Fritzner, not an Alsacian as I believed, but a Prussian to a certainty, who surely struck the blow; his disappearance the day after the crime is the proof of it." "You say that you were not able to procure his address?" "But you, who have other means at your disposal, can find him. He is twenty-seven or thirty years old, of middle height, blue eyes, a blond beard, and a complete blue suit of this cloth." The agent wrote this description in his note-book as the tailor gave it to him.