Sitting astride Chick’s broad shoulders, Nick was able to reach the roof. Beginning at one of the end walls, they proceeded to cover the flat stones of the ceiling with the utmost care. “I can’t stand this much longer,” said Chick, staggering, and only saving himself and Nick a fall by a quick effort. “This gas seems to sap all my strength.” “Hang to it, old man,” returned Nick. “By Jupiter! I’ve struck it! Let me down, Chick.” “If you’ve found the pipe, Nick, plug it up.” “I haven’t found the pipe, and we can’t stop the escaping gas.” “Can’t?” echoed Chick. “No.” Nick jumped from his assistant’s shoulders. “It comes between the joints of those roof stones. If we had tow, and could calk up every crack in the roof, we might save ourselves. But that’s out of the question.” “What a devilish contrivance!” exclaimed Chick. “It’s devilish enough to do for us if we can’t find our way out of this hole.” “You might look for a trap in the roof.” “As soon as you’re able to bear my weight again, I’ll try.” “Try now, old man. Every second is worth its weight in gold.” Nick tried to mount Chick’s shoulders, but Chick was too far gone and could not hold him up. “You get on my back,” said Nick. But the deadly fumes had already weakened the detectives so that it was impossible for them to continue their search for an exit. “Slip off your coat, wrap it around your head, and get down on your knees, your face to the floor.” Nick made the suggestions in a quick voice, at the same time carrying them into effect himself. In this manner a temporary relief was obtained. The foulest air lay near the roof. It would be only a question of time, however, until every particle of air in the chamber would be too deadly to sustain life. The light was still burning, and Nick, with an awkward movement, turned the ray upon his companion. Chick had straightened out along the floor, and was lying still and motionless. “I guess it’s all day with us,” thought Nick. “To think that we are to be done to death like this, and die like rats in a trap!” He felt his senses going and fell from his knees. As he did so, and just at the last moment of consciousness, he thought he saw one of the blocks in the floor begin to rise. Was it an illusion of his disordered senses? It could not be! For, as the stone arose, a draught of fresh air came through the opening it left in the floor. Nick inhaled a great draught of it, and started to his knees once more. The ray from the pocket lamp was focussed upon the stone. Nick turned the ray slightly, and saw the face of a man standing with head and shoulders through the trap. “Patsy!” he called, in a hoarse voice. “Nick, by gum!” CHAPTER X. BREAKING THE NEWS. Patsy had arrived right in the nick of time. He had not tried to get to the saloon before ten o’clock, and he showed up there in the guise of a Swede sailor, “three sheets in the wind.”