“Do!” echoed Waldron, still standing with his back to the door of the little, shabbily furnished reading-room. “Do! I merely ask you for those letters.”

“Which you will never get. I have them here safe in my pocket,” and he drew out a bulky envelope which he exhibited in triumph. “At noon to-day I shall sell them to my friend, Stein, who can easily place them in the proper quarter. It will be my revenge, my dear m’sieur,” he laughed.

“And a pretty revenge—eh?—upon a defenceless girl whom you have deceived—whom you have met in all sorts of odd, out-of-the-way places. I saw you together as far away as Wady Haifa, in the Sudan. And I watched you all the time you were together in Egypt.”

“I think that to discuss this affair further is quite useless,” Flobecq said with an annoyed look. “You can rest assured that neither your bluff, nor any other influence that you could bring to bear upon me, would ever induce me to give up the letters to you.”

“That is your decision—eh? Reflect—because your defiance may cost you more than you imagine.”

“Bah! What do I care for you, a mere British diplomat! What do you know of Secret Service ways, or methods?” he laughed.

“I know this,” was Hubert’s reply, “that if you refuse to give back to me the correspondence of your unfortunate victim you will find yourself in a very awkward predicament here in Paris.”

“Bah! You are only bluffing, I repeat! What, do you think I have any fear of you? You diplomats are merely air bubbles of self-importance. You are so easily pricked.” And he turned from Waldron with an expression of supreme contempt.

“Seven months ago there was an incident at Toulon Arsenal—regarding the Admiralty wireless station there—and you escaped,” Hubert remarked in a low, meaning voice.

“Well?”