In the Old West, Calamity Jane (Jane Russell) -- working undercover to smoke out the gunrunners who sold shootin' irons to hostile Indians -- enters into a sham marriage with so-called painless dentist Peter Potter (Bob Hope). When the Indians lay siege to the couple's wagon train, cowardly Peter cracks jokes at his expense, and it falls to Jane to save the day. But Peter gets the credit, turning him into a target for the Indians and the outlaws.