It's 1878 in the wild American West, and people do what they can to make decent lives for themselves. Tuck Powells is a stoic Wells Fargo detective hired to protect a rich mine owner, George Hearst. Kelly Ryan is a spirited young actress headed West to make her fortune in the theater. Tuck and Kelly are thrown together during a tumultuous stagecoach ride from San Francisco to Deadwood, Wyoming.
In Deadwood, Kelly discovers that her acting job is actually as a waitress in a brothel and ends up killing a lecherous customer in self-defense. Tuck rescues her and helps her to safety, kindling a spark between them that can only grow stronger. Hearst, meanwhile, is slowly building a mining empire that will eventually be the largest in the country, if he can outsmart his devious competitors at the DeSmet Mining Company.
After they've weathered fires, avalanches and snowstorms, Tuck tells Kelly that he's too old for her. She rejects him, and Tuck decides to return to San Francisco with Hearst. But when a flash flood threatens to wipe out the town where Kelly lives, Tuck know he has no choice but to go back for her.