Joe, the Wop, employed in the roundhouse near Lone Point is notified that he has been promoted and will take his place that night as a fireman on the local freight. On his way home he stops at the station to tell Helen, the operator, of his good fortune. As Joe starts down the track towards home, Scarlotta, a member of a notorious vendetta that has marked Joe for death, shoots him from ambush. Helen sees Joe fall in the middle of the track and barely succeeds in dragging him to safety out of the path of the limited. Joe's wound is not serious and that night he takes his place as fireman on the freight. Determined to "get" Joe, Scarlotta visits the station where Helen is still at her key and after binding her and locking her in a closet, throws the switch so that the freight will collide with the cars on the siding. Helen frees herself by tipping over the clothes closet and saves the freight and its crew by reversing the switch. Thwarted again, the Vendetta agent climbs aboard the engine the following morning, overpowers the engineer and ties Joe to the driver's seat after dumping the engineer out of the side door. As the runaway engine (Scarlotta has uncoupled it from the train) proceeds to certain destruction, Helen gives chase on her motorcycle. After a perilous ride across a high bridge, she leaps for the engine cab and pulls herself up by the rope that Scarlotta has used to tie up Joe, the fireman. She is just in the nick of time for the remorseless Italian had tucked a stick of dynamite in Joe's belt and set fire to a short time fuse. As Helen hurls the dynamite from the window it explodes, tearing a great yawning hole in the right of way.