“Nothing now,” Nick answered, quietly, opening the knife’s largest blade. “One of the men who brought us here must have dropped the knife. Turn over, Chick, and I’ll cut off your ropes.” Chick whirled over, and was soon freed of the bonds about his wrists and ankles. Nick then cut the cords from his own feet, and the two detectives arose and stretched their cramped limbs. “Wonder if I shot anybody up there during the set-to?” Nick muttered, closing the knife blade and slipping the knife into his pocket. “Give it up,” answered Chick. “I was down and out about as soon as you were. The instant the light was turned off, somebody let me have it full from behind. Great Scott! My head’s buzzing yet.” “Mine, too.” “I wonder if I’ve been touched?” Chick began, turning his pockets inside out. “Oh, no, I haven’t been touched,” he remarked, dryly; “I’ve been grabbed. I haven’t got so much as a toothpick left. Those longshoremen probably got the rake-off for their trouble.” “I have nothing left but the pocket lamp,” said Nick. “In some way they overlooked that. The thing for us to do is to get out. I have a pressing engagement at Montgomery’s house, in Forty-fourth Street, to-morrow morning at ten. What time do you think it is now?” “No idea.” “It can’t be more than nine or ten.” Picking up a small piece of stone that lay on the floor, Nick started along one of the walls, tapping on every rock. Chick took his cue, and began doing likewise. Suddenly Nick paused. “Smell anything, Chick?” “I was just going to ask you the same question.” “What do you think it is?” “Gas.” “That’s what I think.” Nick flashed the light on his assistant’s face and saw that it had become exceedingly grave. Chick realized what the game was, and it was enough to make him sober. “They intend to kill us with that gas,” said he. “And they’ll do it,” answered Nick, grimly, “if we can’t find the jet and plug it up.” The incandescent light in the pocket lamp, of course, would not ignite the escaping gas, and Nick flashed the penciled beam to every point of the side walls, the floor and the roof. Not a sign of a gas pipe could be seen. But the gas was coming from somewhere, and coming in a quantity that would soon fill the chamber. Breathing was already exceedingly difficult. “Go on tapping the walls,” gasped Nick. “If we don’t find a way to escape, or get next to that gas plug, we’ll be laid out cold.” Goaded by the foul atmosphere, which was rapidly becoming more and more poisonous, the two detectives hastily tapped the walls to their full extent. They found nothing. “It must come from the roof,” said Nick. His voice was hoarse and rasping, and his lungs felt as though compressed under a ton’s weight. “How are we going to do any searching up there?” queried Chick, rising on his tiptoes and stretching his arms. “I can’t come within three feet of the ceiling.” “Take me on your shoulders,” said Nick. This plan was carried out without loss of time.