“Stop,” said the major, truculently. “We must use some discretion here. Are you sure you know what you are talking about, Peret, or are you simply making a wild guess?”

“I know it,” shouted Peret, making a heroic though futile effort to lower his voice. “Ah, it was too simple! Like taking the candy from the mouth of the little one! Oui, m’sieu; The mystery is solved! I stake my reputation on it. I will show you—Stay!”

To the horror of the central office men, he grasped the dignified major by the lapel of his coat and dragged him (not unwillingly) out of his chair and half across the room. When they were well out of earshot of the others, he drew the major’s head down and poured a perfect torrent of whispers in his ear.

Dobson heard the Frenchman out without interruption, but, while evincing the deepest interest, he did not appear to be altogether convinced. However, Peret had once been under his command, and there was no one who had more respect for his ability. It was he himself who, a year or so previously, had characterized the Frenchman as “an accomplished linguist, a master of disguise and one of the most astute criminologists on this side of the Atlantic.”

In his present extremity, moreover, he was like a drowning man clutching at a straw. He was not in a position to reject a possible solution of the mystery advanced by a man of Peret’s ability, no matter how unsound it might appear to him.

“What you say seems plausible enough,” he remarked, when Peret paused for want of breath; “but it is, after all, only a theory. There is not a shred of evidence to give weight to your words.”

“Evidence is sometimes the biggest liar in the world,” said Peret, a little dashed by Dobson’s lack of enthusiasm. “In this case, however, there is, as you say, no evidence of any kind—yet. We must therefore look for it, before it sneaks up on us and bites us. Ah, my dear friend. Think! Consider! Reflect! Why, the thing is as clear as a piece of crystal.”

“What suggestions have you to make!” asked the major, visibly impressed. “I suppose you have in mind some plan—.”

Oui!” cried Peret, with fierce enthusiasm. “Except for one little thing, I ask that you give me a free hand. I will either prove or disprove my theory within twenty-four hours. Your men in the meantime, can make an independent investigation.”

He made several hieroglyphics on a page torn from his memorandum book and handed it to the major. Dobson studied the characters for a moment, and then nodded.