“You, too, under arrest!” gasped Don. “By Jove, this is certainly a weird night!”

“And how about that chap parading around in a peasant’s blouse and wooden shoes?” cried Peur Jamais. “If any one ought to be arrested he’s the one.” He turned to the secret service man. “I demand that you take him into custody. He’s an impostor—a—a——”

“Softly—softly, my young friend,” broke in the mysterious peasant. “I deeply regret that an unpleasant duty had fallen to my lot, particularly as our country has every reason to be grateful to America.”

He threw open his thin blue blouse, at the same instant raising his lantern. And as the yellow light shone on another shield precisely similar to the one which adorned the breast of the other man, both Don Hale and Bobby Dunlap gave voice to exclamations of the greatest surprise and wonderment.

“So you, too, belong to the secret service!” cried Don.

“Can—can you beat it!” came from Bobby, weakly.

“I think it would be a rather hard job,” broke in Jason Hamlin. “And——”

He was interrupted by the third man, who had been a silent witness to the proceeding.

“Let me put in a word,” he exclaimed, authoritatively. “I also belong to the secret service; and I wish to say to you young Americans that you are at liberty to return to the villa—the headquarters of the Lafayette Escadrille. Under no circumstances, however, are you to leave it until this affair has been entirely cleared up. I and my camarades are not here to answer questions. Your captain has already been notified. Remember, you are technically prisoners. This may seem harsh, ungrateful, and unappreciative perhaps of the work you have done for France, but the law knows no sentiment; it is cold and pitiless. Now you may go.” Addressing his compatriots, he added: “Come, Messieurs.”

Thereupon the three secret service men, with words of adieu, turned toward the house.