Karen Tandy (Susan Strasberg) enters a San Franisco hospital suffering from a growing tumor on her back. To the doctors (Jon Cedar and Paul Mantee) think it's a living creature, a fetus is being born inside the tumor. To fortune teller Harry Erskine (Tony Curtis) says it's nothing until his client (Lurene Tuttle) says strange languages, and kills herself by falling down a flight of stairs. And after one of the doctor's cut his hand. Erskine seeks help from another fortune teller Amelia Crusoe (Stella Stevens) and her husband (Hugh Corcoran) to find what is going on. When Karen's tumor gets larger, Dr. Snow (Burgess Meredith) begins to think it is a 400 year old Indian Spirit who wants revenge. Erskine goes to South Dakota to find John Singing Rock (Michael Ansara) a witch doctor to send the Indian Spirit back to where he came. The Indian Spirit comes out of Karen's tumor. But will he take over before Singing Rock can send him back?