Kinney, the old section boss, is delighted when Helen agrees to take his boy, Jimmie, in hand and teach him telegraphy. The boy proves an apt pupil and soon masters the code, but is heart-broken when the Chief says he is too young to take a regular shift. Jimmy swallows his sorrow and helps Helen and the lineman construct a "loop" over to her house, and often remains in the station while she slips home for her meals. Jose, a Mexican track hand, reports for section work much the worse for liquor. Kinney fires him. He hangs around and learns that a registered pouch has been lost off the mail train. While Jose plans a search for it, Jimmy shows up from a fishing trip with the lost sack. Helen locks it in the safe and leaves Jimmy in charge of the station. Jose and his gang bind up Jimmy and leave him in the lineman's room above the station office, where Helen's private wire terminates. By some good contortion work Jimmy reaches the key and telegraphs the alarm to Helen. A hobo has seen the gang board a passing freight and helps Helen put a gasoline hand car in commission for giving chase. Running down the siding, Helen leaps from the handcar to the freight. Seeing a switch, she tumbles off, but recovers in time to throw it and cause the rear of the freight to sideswipe the handcar on which the Mexicans are attempting a getaway. The bandits are completely done up, the pouch is recovered, and Helen makes sure that Jimmy earns the reward of a job.
—Moving Picture World synopsis