When an ancient stone tablet is unearthed in the Mid East and brought back to American for study, a deadly mystical force is unleashed. Kolchak follows a series of deaths where healthy young men were found dead of heart attacks, each accompanied by the bodies of women who seemed to have died in unrelated circumstances and locations. Kolchak discovers that the murders are the work of a Succubus, a Sumerian demon that assumes the form of recently deceased women and lures men into her deadly embrace.