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.