“Partly for personal reasons, largely because I want to have a hand in this case.”

Gibelin moved uneasily.

“You think this case so interesting?” put in the judge.

“The most interesting I have ever known,” answered the other, and then he added with all the authority of his fine, grave face:  “It’s more than interesting, it’s the most important criminal case Paris has known for three generations.”

Again they stared at him.

“My dear Coquenil, you exaggerate,” objected M. Simon.  “After all, we have only the shooting of a billiard player.”

M. Paul shook his head and replied impressively:  “The billiard player was a pawn in the game.  He became troublesome and was sacrificed.  He is of no importance, but there’s a greater game than billiards here with a master player and—­I’m going to be in it.”

“Why do you think it’s a great game?” questioned the judge.

“Why do I think anything?  Why did I think a commonplace pickpocket at the Bon Marche was a notorious criminal, wanted by two countries?  Why did I think we should find the real clew to that Bordeaux counterfeiting gang in a Passy wine shop?  Why did I think it necessary to-night to be on the cab this young American took and not behind it in another cab?” He shot a quick glance at Gibelin.  “Because a good detective knows certain things before he can prove them and acts on his knowledge.  That is what distinguishes him from an ordinary detective.”

“Meaning me?” challenged Gibelin.

“Not at all,” replied M. Paul smoothly.  “I only say that——­”

“One moment,” interrupted M. Simon.  “Do I understand that you were with the driver who took this American away from here to-night?”

Coquenil smiled.  “I was not with the driver, I was the driver and I had the honor of receiving five francs from my distinguished associate.”  He bowed mockingly to Gibelin and held up a silver piece.  “I shall keep this among my curiosities.”

“It was a foolish trick, a perfectly useless trick,” declared Gibelin, furious.

“Perhaps not,” answered the other with aggravating politeness; “perhaps it was a rather nice coup leading to very important results.”

“Huh!  What results?”

“Yes.  What results?” echoed the judge.

“Let me ask first,” replied Coquenil deliberately, “what you regard as the most important thing to be known in this case just now?”

“The name of the woman,” answered Hauteville promptly.

“Parbleu!” agreed the commissary.

“Then the man who gives you this woman’s name and address will render a real service?”

“A service?” exclaimed Hauteville.  “The whole case rests on this woman.  Without her, nothing can be understood.”

“So it would be a good piece of work,” continued Coquenil, “if a man had discovered this name and address in the last few hours with nothing but his wits to help him; in fact, with everything done to hinder him.”  He looked meaningly at Gibelin.