Luke Beamish is the engineer of the Isobel, an old iron steed, and Cannonball Casey handles the throttle of the Mogul, a modern locomotive. Cannonball falls in love with Doris, Luke's daughter, who is greatly admired by Jack Sweeney, the railroad president's son. Doris rejects Casey's affections, considering him a bully, and consequently Casey challenges Jack to a wrestling match at the picnic. Superintendent Dugan, hearing of the match, plots to save young Sweeney from destruction; Luke learns the secret of defeating Casey, while Luden is lured away by Dugan; but the boy returns in time to knock out his rival. When Doris elopes with Jack, his father gives chase in a locomotive. Casey, relenting in favor of Jack, restrains Sweeney until the marriage has been legalized.