Billy Warren, timekeeper on the construction job, arouses the enmity of Brent and Easton when he resents their bullying of the other men. Pay day finds the men celebrating in riotous fashion, and Brent in a crazed moment breaks into the station and attacks Helen. Her cries bring Warren, who trounces the bully. Brent and Easton then lay in waiting for Warren and, after a vicious blow has made him unconscious, throw him on a flat car which is started down grade, gaining momentum every second. Helen learns of the action and, on wiring ahead, finds that a passenger train is speeding towards the flat car so that only desperate measures will save the day. She climbs quickly to the seat of her motorcycle and sets out over the tracks after the flat car. Just as she is overtaking it an express depot looms up ahead and seems certain to halt her progress along the side of the track. But without hesitating a second to count the risk, Helen drives straight ahead, up the runway of the baggage platform and, as she reaches the top and comes abreast with the flat car, swerves quickly towards the tracks, dropping to the flat car as she passes through the air above it. While she is struggling with the brakes a track walker sees her peril in time to send the flat car on a siding just as the passenger speeds by. Before Helen can bring the ear to a stop, however, it smashes through the two-story signal tower at the end of the siding, Helen leaping to the ground with the injured Warren just a second before the crash.