Pregnant Jenny (Chatterton) loses both her father and lover during the 1906 San Francisco earthquake. Without a home, she eventually gives up her illegitimate son to a wealthy couple and becomes a successful bordello madam on the Barbary Coast. Son Dan (Cook) grows up to be a crusading district attorney, but a criminal cohort (Calhern) of Jenny's wants him dead. Her actions save Dan but lead to her own downfall.