ut his hand, and the
wall gave slightly. He drew the revolver and waited, dreading what
might next occur. He heard soft footsteps outside the door, and,
raising the revolver, pulled the trigger. The trigger snapped
harmlessly. He had been tricked, tricked all around.

"Is the oubliette prepared?" whispered a voice outside.

"All ready for him. Twelve feet of water. He'll drown like a rat."

"Good. A slow death, like a rat in a trap--like we served the other
two. Then get rid of his body the same way."

"A stone on it, and the river?"

"Yes. They never come up again."

The voices died away along the corridor, and Philo Gubb was left in
utter silence. Oubliette! The fate of the detectives of "The Pale
Avengers" was to be his! Suddenly the room began to quiver. The floor
and the walls trembled and creaked, and Philo Gubb threw himself once
more against the door. He shouted and beat upon it with his hands.
Inch by inch, creaking and swaying, the room glided downward. The
door seemed to glide upward beyond the ceiling, giving place to a
solid wall. He turned and beat on the side of the room, and it gave
forth a hollow sound. As he moved, the room swayed under his feet. He
was doomed!

Alone in the darkness, his fear suddenly gave way to a feeling of
pride. He was dangerous enough, then, to be thought worthy of death?
His last drop of doubt oozed out of his mind. He was--he must be--a
great detective, or such means would not have been taken to get rid of
him. He felt a sort of calm joy in this. His murderers knew his
prowess.

Locked in the room, going down to certain death, he exulted. And if he
was as great as all that, it could not be that his position was
hopeless. Time and again Carl Carroll, the Boy Detective, had been in
equally precarious positions, but in the end he had brought the Pale
Avengers low. And what a boy, untrained, could do, a graduate of the
Rising Sun Correspondence School of Detecting ought to be able to do!
He drew his knife from his pocket and cut into the wall-paper of the
side wall.

Being a paper-hanger, the first touch of his hand against the side
wall had told him the wall-paper was pasted on canvas and not on a
solid wall, and now he ripped the canvas away. The wall was of rough
boards, scarred and marred. The opposite wall was the same. He kneeled
on the bed and tried the rear wall. He felt the plastered wall gliding
upward. He stood on the bed and ripped the canvas ceiling away.