Faster--faster--then the impact, like crashing into a stone wall. They were within the snowshed now, the auger boring and tearing and snarling like some savage, vengeful thing against the solid mass of frigidity which faced it. Inch by inch for eight feet it progressed; the offal of the big blades flying past in the glare of the headlights like swirling rainbows; then progress ceased, while the plow ahead, answered by the engines which backed it, shrilled the triple signal to back up, out into the air again, that the ice crews might hurry to their tasks. The engineer opened the cab window and gratefully sucked in the fresh, clean air. "Eight feet--that's all," he mused. "Eight feet at a time." Then, noticing Houston's attention, he went on: "It's all the big screw can make. Got a hood on the front, you know, protecting the blades. It's eight feet from the front of that hood to the first trucks. When it's scooped that out, it's the finish. The wheels hit ice, and it's either back out or get derailed. So we back. Huh! There she goes again. Keep your nose in your elbow, youngster, this time. We're goin' back pretty sudden. We'll get gas." The screaming of the whistles faded, giving way to the lurching of steel monsters as they once more crawled within the blackness of the smoke-filled, snow-choked shed. Deeper they went and deeper, the shouts from without fading away, the hot, penetrating sulphur smoke seeping in even through the closed cab, blackening it until the electric lights were nothing more than faint pinpoints, sending the faces of the men to their arms, while the two crouched, waiting anxiously until the signal should come from ahead. A long, long moment, while the smoke cut deeper into protesting lungs, in spite of every effort to evade it, while Old Andy on the engine seat twisted and writhed with the agony of fading breath, at last to reel from his position and stumble about in the throes of suffocation. At last, from ahead, came the welcome signal, the three long-drawn-out blasts, and the engineer waved an arm. "Pull that rope!" he gasped toward the first fireman. "For God's sake, pull that rope! I'm about gone." A fumbling hand reached up and missed; the light was nearly gone now, in a swirling cloud of venomous smoke. Again the old engineer stumbled, and Houston, leaping to his side, supported him. "Find that rope--" "I can't see! The smoke--" Desperately Houston released the engineer and climbed upward, groping. Something touched his hand, and he jerked at it. A blast sounded--repeated twice more. In the rear the signal was answered. Out ground the train to freedom again. It was the beginning of a night of an Arctic hell.