Bill Mogrotty, an ex-railroad employee, rebels at his wife's upbraidings and leaves his humble home to follow the life of a hobo. Mrs. Mogroytty and her small daughter, Rosy, left alone, make a pitiful attempt to eke out a living by taking in washing. Bill's wanderings throw him into the company of other hobos and one day he chances to overhear some of them plotting to wreck and rob the fast express. His tramp life has pretty well disgusted him and when he realizes what his companions are about to do he suddenly resolves to save the train. He sneaks away from the others and manages to flag the train and capture the would-be wreckers. The express train conductor persuades Bill to accompany him to the city. In the meantime Rosy, the child, has been sent to gather firewood in the railroad yard. Seeing some shavings in an open box car, she climbs in. She is no sooner in the car than the train starts and Rosy, thoroughly frightened, is carried away. Bill is presented to the road superintendent, and for his bravery is given a substantial sum of money and a pass for himself. As they are passing out of the railroad yard their attention is suddenly arrested by the sight of a child, clinging to the open door of the swiftly moving freight train. The superintendent flags the train and when the child is rescued, Bill discovers that she is none other than his Rosy. That night there is a happy family reunion in the Mogrotty home.