The Hazards of Helen: Episode 3 - The Girl at the Throttle.

Blake, fireman of a light engine, receives a message that his wife is dangerously ill. Benton, his engineer, allows Blake to catch an eastbound passenger train. A hunter shooting as the light engine is passing, wounds Benton who drops unconscious. The sportsman reports the accident. Helen, a telegrapher, receives word of the runaway train. Climbing into the cab of a locomotive in a siding, Helen jerks the throttle wide open. The engine rushes after the endangered express. Discovering his train is being pursued, the conductor of the Eastbound Express gives the signal to stop. Helen slows her engine down and tells of the danger. While the Eastbound locomotive goes to meet the runaway, Helen's engine draws the cars to safety. The runaway is halted in the nick of time. Helen's superb heroism results in her being showered with offers of marriage. But she enjoys her hazardous adventure too much to marry anyone yet. —Moving Picture World synopsis