When Harriet Copley refuses to marry Douglas Williams, he begins to drink, then goes West. In a mining town, Douglas meets Nell, a dance hall girl known as "The Mountain Rat," who is touched by his plight and nurses him back to health. Nell stakes Douglas to a claim, and although he is still in love with Harriet, he marries Nell. Meanwhile, Harriet changes her mind and comes to the mining camp along with Douglas' mother. Ashamed of his new wife, Douglas keeps his marriage a secret, thus infuriating Nell, who tells Harriet the truth. Douglas threatens to leave Nell, provoking disconsolate entreaties from his wife which are overheard by Steve, a rival for Nell's affection. Steve tries to shoot Douglas, but Nell intervenes, causing Steve's gun to misfire. She falls to the ground, and Douglas, believing her to be dead, realizes that he loves her. Nell, however, is uninjured, and after upbraiding Douglas, she forgives him.

Director:
James Kirkwood	Director
Cast:
Henry B. Walthall	as Douglas Williams
Dorothy Gish	as Nell, "The Mountain Rat"
Irene Hunt	as Harriet Copley
Donald Crisp	as Steve
Josephine Crowell	as Mrs. Williams
Writer:
Frank E. Woods	Scen
Mary Rider Mechtold	Story

Sources vary on plot information. Because the facility where this film was made was commonly known as the Reliance-Majestic Studio, some sources referred to the production company's name as "Reliance-Majestic."