It is 1876, and San Francisco, the freewheeling "Paris of the West," is in the fierce grip of a record-breaking heat wave and a smallpox epidemic. Through the window of a railroad saloon, a young woman called Jenny Bonnet is shot dead. The survivor, her friend Blanche Beunon, is a French burlesque dancer. Over the next three days, Blanche will risk everything to bring Jenny's murderer to justice-if he doesn't track her down first.