The blackened stokers looked like grim demons of the fiery pit as they labored at the coal, which they were shoveling into the mouths of the greedy furnaces. The shifting glow was caused by the opening and closing of the furnace doors, which clanged and rang. For a moment the pit below would seem shrouded in almost Stygian darkness, save for some bar of light that gleamed out from a crack or draft, and then there would be a rattle of iron and a flare of blood-red light that came with the flinging open of a furnace door. In the glare of light the bare-armed, dirt-grimed stokers would shovel, shovel, shovel, till it seemed a wonder that the fire was not completely deadened by so much coal. Sometimes the doors of all the furnaces would seem open at once, and the glare and heat that came up from the place was something awful. Merry wondered how human beings could live down there in that terrible place. Some of the men were raking out ashes and hoisting it by means of a mechanism provided for the purpose. Frank pitied the poor creatures who were forced to work down in that place. Yet he remembered it was not so many months since he had applied for the position of wiper in an engine round-house, obtained the job, and worked there with the grimiest and lowest employees of the railroad. There was something fascinating in the black pit and the grimy men who labored down there in the glare and heat. Frank was so absorbed that he heard no sound, received no warning of danger. Merry leaned out over the edge of the iron grating. Something struck on his back, he was clutched, thrust out, hurled from the grating! It was done in a twinkling. He could not defend himself, but he made a clutch to save himself, caught something, swung in, struck against the iron ladder, and went tumbling and sliding downward. At the moment when Frank was attacked, a glare of light had filled the pit. One of the stokers had turned his back to the gleaming mouths of the furnaces and looked upward, as if to relieve his aching eyes. He saw everything that occurred on the grating. He saw a man slip down the ladder behind Frank and spring on his back. He saw that man hurl Frank from the grating. The stoker uttered a shout and ran toward the foot of the ladder, expecting to find Frank laying there, severely injured or killed. He was astounded when he saw the ready-witted youth grasp the grating, swing in, strike the ladder, cling and slide. Down Frank came with a rush, but he did not fall. He landed in the stoke-hole without being severely injured. He was on his feet in a twinkling, and up that ladder he went like a cat. His assailant had darted up the ladder above and disappeared. Merry reached the grating from which he had been hurled, and then he ran up the other ladder. He was soon in the engine-room.