He was twisting wheels with all his might. As fast as they could the two boys went from car to car, setting the brakes. But in spite of their efforts, and the efforts of another brakeman besides the one they had spoken to, the speed of the runaway freight train increased. The grade was a steep one, and down the hill the uncontrolled cars rushed. "I don't believe we're going to stop," said Jack. "Shall we jump?" asked Mark. "Not if you want to get a job in the mill or factory," replied Jack. "I reckon if you or I jumped that would be the last of us." With a rush and a roar the train continued to speed along. The trees and telegraph poles whizzed past so quickly as to be almost invisible. "I guess this is Millville," said Mark, as the runaway train passed a station, on several sides of which there were large buildings to be seen. So fast was the runaway train going now that the boys had to lie down on their faces and cling to the run-boards on top of the box car to avoid being jolted off. The wind fairly whistled in their ears. Through the town they rushed, observing, as by a flash, the white, frightened face of the station agent as he watched them go past. "Do you think there'll be a smash-up?" asked Mark. "I don't see how it can be avoided," replied Jack. "This track has to come to an end somewhere. When it does, look out, that's all!" On and on rushed the train! It's speed was now fearful, for the down grade had increased. It was of no avail to twist the brakes, for no strength would avail to slacken the awful speed. The boys, in common with the brakemen, could only cling and wait in terror for what was to come. The cars swayed as they went around a curve. Jack lifted his head and peered forward. "Hold fast!" he shouted. "We're going to strike something in a minute!" He had looked up in time to see that the track siding came to an abrupt end about a quarter of a mile further on, the rails stopping in a sand bank. Hardly had the boys time to take a tighter grip with their fingers on the boards to which they were clinging, when the whole string of freight cars seemed to crumple up like a collection of paper vehicles. There was a grinding, sickening crash, a succession of heavy jolts, a piling up of one car on top of another, a splintering of wood, a rending of iron and steel, and then with one terrible smash, with one final roar, the runaway freight piled itself up in a mass of shattered cars against the sand hill, at the base of which the rails came to an end. It was a fearful wreck. "Hold fast!" were the last words Jack cried to his companion. His voice sounded faint above the din. "Where are you, Jack?" he heard Mark shout in reply. Then all became dark, and the boys lost their senses as they were hurled into the splintered mass of wreckage. CHAPTER III A STRANGE RESCUER