Steve Nelson, a clever crook, arrives at the little station where Helen is operator. He lives quietly at the village's little boarding house preparing for a coup when Helen receives instructions that lead her to suspect Steve. By a clever ruse she succeeds in exposing him and making him prisoner in the station. He escapes and flees on a stolen engine. Helen follows on another locomotive and after a thrilling chase overhauls him, couples the two engines together, and then crawls on the swaying coupling to the other locomotive to bring Nelson to bay.
—Moving Picture World synopsis