Bob Fleming, cowboy and U. S. marshal, is racing a train on horseback. From the train pretty Barbara Benton attempts to take a photograph of him, but as she leans forward her hat blows out the window. Bob catches the hat and leaps onto the train, but he is stopped by a porter. Bob pulls his gun in order to make the man step aside. The passengers, seeing this action, assume it to be a holdup and deposit their valuables in the hat. Arriving at the ranch, Barbara learns that Bob works there as a hand. The sheriff, who is also attracted to Barbara, arrests Bob as a cattle thief. Barbara, learning that the sheriff and her father are the leaders of a group of thieves, is forced to testify falsely that Bob is a train robber, and he is sentenced to be hanged. She herself is taken by the sheriff as hostage. But Bob escapes, forms a posse, kills the sheriff, and frees Barbara.