Jack Bradford, son of Bankson Bradford, multimillionaire railroad builder returns home from a night's dissipation, his father denounces him, declaring that he must find a home elsewhere. Jack leaves in anger. Halsey Crompton, Bankson's construction superintendent, is in Denver and receives a telegram that the S. and L. railway is building a new road to parallel the Bradford line to Lamson, and that trouble is expected between the rival camps. Meeting Jack on the street, Crompton asks Jack to go west with him, turn over a new leaf, work as a railroad builder and hide his identity by assuming the name of "Jim Stokes." Jack agrees. Crompton and Jack arrive at the station near the rival construction camps, Jack meets Mary Worth, telegraph operator, and daughter of Jason Worth, engineer of the Bradford construction train locomotive. Bud Stanger, superintendent of the rival work on the S. and L., foments a terrific battle between the laborers in both camps. Stanger and his plotters then plant dynamite under a bridge on the Bradford road, setting a device to blow up the structure when Crompton, Jack and his crew are at work. Stanger then goes to Lamson depot to wreck it. Mary's father is knocked unconscious by Stanger. Mary escapes to her father's locomotive. Stanger follows and fells the fireman. Mary starts the locomotive, having heard Stanger declare that the bridge is to be blown up. Stanger climbs aboard and battles with Mary. Jack, on horseback, sees the struggle, leaps from his horse into the cab and throws Stanger into a chasm. Mary is unable to stop the locomotive. To escape death both leap from the locomotive to the river, eighty feet below. They swim ashore and join the Crompton crew. Jack and Mary warn the workmen who escape safely, just as the new structure is blown to atoms. Crompton, Jack and Mary go back to Lamson station where they find that her father has recovered from Stanger's blows. Later Bradford arrives, asks to be shown the heroic "Jim Stokes" and Mary. When he sees his own son he almost collapses with joy to find that his boy has redeemed himself. The betrothal of Jack and Mary follows.
