"I agree," he said. "If you want to go, Hal, we'll wait here."
"Good. If I have not returned in fifteen minutes you will know something has happened. In that event, I would advise that you all come down together, lend me a hand if I'm still in the house and in condition to be helped, and we'll all make a break for the airship."
"That is satisfactory," said Major Derevaux.
"And if I'm not in condition to be helped," said Hal, "go along without me. You will not have time to be burdened with excess baggage."
The others nodded and Hal gently slid open the secret door.
"Remember," he whispered back, "fifteen minutes."
The door closed behind him.
Hal made his way quietly through the two rooms that led to the stairs, and as quietly descended. As he passed through the parlor and approached the room in which he had met Major Derevaux the night before he heard the sound of voices. He paused and listened.
One he made out was a male voice, which he took to belong to a German officer. The second was that of Mademoiselle Vaubaun. Then a third voice boomed out. This, Hal knew, was that of a second German.
Hal approached the door and put his eye to the key-hole. Then he started back and whipped out his revolver.