They took a desperate chance on foul air and plunged down the drift, pausing only now and then when they came to the first side drifts to make sure of their course. They were informed by the plans that they had barely three hundred feet to explore, yet they had gone even farther than that before they came to a halt, a threatening one, for directly ahead of them the timbering had given way, the shaft caved, and there seemed at first no opening through the debris. "Well, this looks pretty tough!" exclaimed Bill, stooping down and examining the face of the barrier. His companion lighted his own candle and together they went over the face of the obstruction. "It looks to me as if we could open her up a little if we can shift this timber here and use it as a lever," he said, pointing to one projecting near the roof. "May bring the whole mountain down, but it's our only chance," agreed Bill. "Here she goes. Stand back. No use in both of us getting it." He caught the end of the timber in his heavy hands, planted his feet firmly on the floor and heaved. The big timber creaked, but did not give. Again he planted himself and this time his great shoulders seemed to twist and writhe until the muscles cracked and then, with a crash, the barrier gave way. He sprang back with amazing quickness and they ran back up the drift for twenty or thirty feet while the mass again readjusted itself and settled slowly into position. A cloud of dust bellowed toward them, half-choking them with its gritty fineness, and then, in a minute, the air had cleared. They went cautiously forward. "Well, we got some farther, anyhow, unless she comes down while we're working through. We've got a hole to crawl into, and that's something," the big miner asserted. Before he could say anything more Dick had crowded him to one side and was entering the aperture. He had prevented his partner from taking the first perilous chance. Painfully he made his way, while the man behind listened with terrified apprehension; for none knew better than he the risk of that progress. "All right, but be careful," a voice came to him faintly from the distance. "She's bad, but the air over here seems good. It's a close shave."