Rupert Winslow, traffic superintendent of the railroad that employs Helen as operator at Lone Point, receives a telegram stating that his wife, who is ill, will be on the midnight express. He calls in Summers, a veteran brakeman on the passenger run and instructs him to watch over Mrs. Winslow and to sidetrack her sleeper if she requires medical attention. Near the Lone Point station the superintendent’s wife takes a turn for the worse and Helen, on night duty at Lone Point, is appealed to. She rouses Dr. Harris, whose headquarters are at the Burro Mine nearby. Meantime the sleeper has been set out on the Lone Point siding. Helen telegraphs Winslow, who charters a “special.” Careless switching at the Burro Mine sets two cars running down the siding upon which the sleeper stands. Helen makes use of the doctor’s automobile and manages to switch the runaway cars onto the main track. Having saved the sleeper, she sets out to warn the special. Reckless of her own danger, she makes a flying leap from the hood of the auto to the ladder of the box car and, climbing up, sets the brakes. Running forward, she signals the approaching special, which is brought to a grinding stop with only a few feet to spare.