Barney Slaney, an Irish mine worker in Tennessee, is trained by his father Mike to become an engineer in accordance with his deceased mother's wishes. As an adult, Barney works as a fireman for engineer Mileaway on the local train. Barney marries Marybelle Evans, but one day returns to find her making love with Grover Perkins, with whom Barney has feuded since he was a child. Barney is enraged and kills them, and after giving himself up, is sentenced to life imprisonment. To his horror, Barney discovers that Grover's brutal brother Ed is the foreman of the chain gang he works on, and Ed particularly picks on Barney. When an epidemic visits a local town, the prisoners are set to work digging graves, and Barney pulls Ed into a grave and knocks him out. A riot follows, during which Barney and other prisoners escape. Barney evades the manhunt, and seeks refuge at a farm recently visited by the pestilence. He befriends Lorraine, whose parents have just died, and after burning the house, they run away. After some complications, Barney and Lorraine cross the state line into a new life together.