“I suppose you know,” said Duval, “that now you have seen me without my mask you will never leave this house alive.”

“I suppose that is your idea,” said Hal.

“You’ll find that I have the right idea.”

“Tell us your real object in coming here,” said Duval’s lieutenant.

“I have told you,” replied Hal.

“That,” said the lieutenant, “is a lie.  It’s too absurd.  I guess I’ll search you.”

He proceeded to do so while Duval kept Hal covered.  There was not much to be found—­but one thing that Hal feared he would discover and which he realized he should have dropped with the revolvers under the bed.

His searcher found it, drew it forth, and, with an exclamation of triumph, held it up for Duval to see.

It was the police whistle General Gallieni had given him.

“So!” he exclaimed.  “A police spy, eh!  I thought so.”

Hal shrugged his shoulders.

“Well, you have me,” he said.  “What are you going to do with me?”

The two men laughed.

“I guess you won’t be as much surprised at what we are going to do as the manner in which we are going to do it,” replied Duval, with an evil leer.

“How?” asked his lieutenant.  “Water?”

“Right,” was his chief’s reply.  He turned to Hal.  “This house,” he explained, “is on the very bank of the River Seine.  Perhaps you have skirmished about in the rear?”

Hal shook his head negatively.

“Well, such is the case.  In the cellar is a neat little room of four solid walls—­no windows.  There is a slight crack at the bottom, and through this, by a contrivance of my own, I can let in the waters of the river.  The door is solid, and, once locked in, you cannot get out.  I believe that this is a fitting death for a police spy.  What do you think?”

Again Hal shrugged his shoulders.

“One way is as good as another,” he said briefly.  Duval turned to his companion with a laugh.

“Quite a brave man we have here, eh?”

“Quite,” returned the other.  “However, I guess he’ll change his tune when the water gets up to his neck.”

“Right you are,” was the reply.  “But what do you say?  Shall he not sup with us first?”

“A good idea!” exclaimed his lieutenant.

Hal had been thinking rapidly.  The men still held their revolvers in their hands, but they no longer covered him.  Taking advantage of this fact, Hal suddenly dived under the bed and his two automatics were once more in his hand.

But the two men were after him in an instant.  Before he could turn and bring his weapons to bear they had him covered, while Duval cried out: 

“Come out from there, or I’ll put a hole through you.”

Hal realized that he could not hope to dispose of his two enemies, so quickly shoving the two revolvers into his clothes, he once more emerged and got to his feet.