"Precisely. I mean that with all your cleverness and with a distinct advantage in position, here on the Champs Elysées with policemen all about us, you cannot arrest me."

"We'll see about that," answered M. Paul, a grim purpose showing in his deep-set eyes.

"I say this in no spirit of bravado," continued the other with irritating insolence, "but so that you may remember my words and this warning when I am gone." Then, with a final fling of defiance: "This is the first time you have seen me, M. Coquenil, and you will probably never see me again, but you will hear from me. Now blow your whistle!"

Coquenil was puzzled. If this was a bluff, it was the maddest, most incomprehensible bluff that a criminal ever made. But if it was not a bluff? Could there be a hidden purpose here? Was the man deliberately making some subtle move in the game he was playing? The detective paused to think. They had come down the Champs Elysées, past the Ansonia, and were nearing the Rond Point, the best guarded part of Paris, where the shrill summons of his police call would be answered almost instantly. And yet he hesitated.

"There is no hurry, I suppose," said the detective. "I'd like to ask a question or two."

"As many as you please."

With all the strength of his mind and memory Coquenil was studying his adversary. That beard? Could it be false? And the swarthy tone of the skin which he noticed now in the improving light, was that natural? If not natural, then wonderfully imitated. And the hands, the arms? He had watched these from the first, noting every movement, particularly the left hand and the left arm, but he had detected nothing significant; the man used his hands like anyone else, he carried a cane in the right hand, lifted his hat with the right hand, offered the envelope with the right hand. There was nothing to show that he was not a right-handed man.

"I wonder if you have anything against me personally?" inquired M. Paul.

"On the contrary," declared the other, "we admire you and wish you well."

"But you threaten my dog?"