Billy turned the dark slide in his lantern. Henri and Reddy followed the cue.
Somebody or something was moving in the passage on the other side of the wall.
That somebody or something suffered a bump of some sort or other—a sound like the overturning of a chair.
Then a muttered oath in French. The somebody or something was human, and French.
The boys backed up into the darkest corner of the treasure house.
The grated window cast only a dim light into the room, but that line streaked straight across into the opening in the wall directly opposite.
The head and shoulders of a man appeared in the opening!
Even in the half-light Henri recognized the soldier who had lost the flagon and the suspicious tapper on the oak around the fireplace in the dining-hall.
From that panel in the dining-hall to the treasure house Henri, in his haste, had neglected to close the other slides, and even the plate over the stairway behind him.
He had carried a light chair from one of the upper chambers so that he could get back into the treasure house without a boost. It was over this that the trailing chasseur had stumbled, and which also gave the red-trousered sleuth the very clew he needed as to the whereabouts of the mysterious party who had taken the flagon from under his very heels.