In an enigmatic, alien landscape, Jerzy Colsowicz, John Huston experiences a vision of a powerful, destructive storm born from a young human girl, delivered by Jesus Christ, Franco Nero, who speaks to his disciples about an ancient, interstellar conflict between Zatteen and his benevolent arch-rival Yahweh. Zatteen, an evil force with immense psychic powers, escaped to Earth centuries ago; though Yahweh eventually tracked him down and killed him, his spirit lingers in the minds of humanity, waiting for a chance to reemerge. The figure explains that Zatteen fathered dozens of children with human women, and that these descendants still populate the world.
Back on Earth, the drama centers on a professional basketball game at The Omni in Atlanta. Raymond Armstead, Lance Henriksen the new owner whose wealth remains shrouded, sits courtside and pledges victory at any cost, hinting that his money comes “from God.” He is part of a secret circle of Satanists who want Zatteen's resurgence. His associate Dr. Walker, Mel Ferrer, reminds him that Barbara Collins is a crucial conduit to distill Zatteen’s powers into a corporeal form. Barbara Collins, Joanne Nail, is a central figure in the plan, and her 8-year-old daughter Katy Collins, Paige Conner, already displays frightening psychokinetic abilities, a trait the Satanists seek to weaponize. Katy’s powers begin to influence events, helping Raymond’s team clinch victories on the court.
Colsowicz, a figure with powers akin to Katy’s, is dispatched to Earth by the Christ-like guide, accompanied by a small retinue of apostles. He observes Katy from a distance and soon becomes acquainted with Barbara’s new maid, Jane Phillips, Shelley Winters, who senses the lurking malice in Katy—an intuition born from having once borne a child with similar abilities. As Katy grows bolder, she uses her gifts to advance the Satanists’ goals, triggering a string of fatal accidents that target their enemies. Barbara is accidentally paralyzed by a gunshot wound, leaving her wheelchair-bound and vulnerable.
Detective Jake Durham, Glenn Ford, investigates the spate of deaths, but his pursuit is cut short when he is killed in a car accident engineered by the Satanists. The situation escalates: Raymond cannot seduce Barbara, so the circle escalates to more violent methods. Barbara becomes pregnant again, but her ex, Dr. Sam Collins, Sam Peckinpah, intervenes and arranges an abortion. When Barbara returns home, she is assaulted by Raymond and Katy, who attempt to finish her off by tying a wire around her neck and pushing her down the stairs in her chairlift. At the crucial moment, Colsowicz intervenes and calls forth an army of doves to thwart Katy and strike down Raymond. The next day, the remaining Satanists are found dead at their round table, a grim aftermath attributed to Colsowicz’s intervention.
Colsowicz returns to the Christ-like figure and presents Katy, who is now bald and seemingly cleansed of her malice. The film closes on a quiet, hopeful note, with Katy smiling and embracing the envoy, who reinforces the message that children are not to be harmed.
