Dr. John Carter, a rather starchy young physician from Boston, is on his way to San Francisco. When a frontier town is stricken by a smallpox epidemic, the doctor reluctantly joins forces with the lawless Belle Starr to rush aid to the stricken people.

A man on parole falls in love with a girl who has been seeing a hoodlum. The hoodlum warns the paroled man to stay away from the girl and when he refuses he schemes to make his rival violate his parole.