A moment later there came a muffled voice from below.
"Right you are, mate."
Dragging Colin's feet toward the edge, the other two men jerked him roughly from the ground. The next instant his legs were dangling in space, and with the iron rungs bumping against his back he slid rapidly down into the darkness below.
Just before he reached the bottom he felt himself clutched round the waist by a pair of strong arms. Then he was lifted clear of the ladder, and dumped heavily on to a damp stone floor.
After a brief interval "Spike" Cooper also descended, and, producing an electric torch, switched on the light. Colin saw that they were in a large cellar, the walls of which were dripping with wet slime. Except for the trapdoor there appeared to be only one other opening—a heavily barred grating some eight feet from the floor.
Bending down over his prisoner, "Spike" Cooper flashed the light full in his face.
"That was a dandy fight of yours, mister," he drawled slowly, "and I'm real sorry we got to put you through it."
Colin looked up at him unflinchingly. "You seem to take a long time about committing a murder," he said. "Why don't you finish the job and clear out?"
The other shook his head. "That's just the trouble," he replied, with a touch of regret in his voice. "In order to suit the party that's arranging this little affair you got to be found drowned—picked out of the Thames. See, mister?"
Colin glanced round, and in a sudden flash the real meaning of the dripping walls became hideously apparent. With a strong effort he managed to control his voice.