On the outskirts of a quiet town, Witch Mountain looms as a rock formation whispered to hide powerful secrets. One night, Zoe Moon, a young waitress, watches in awe as infant twins, Anna and Danny, appear behind the diner in a shaft of purple light, leaving her stunned and fainting from shock. A local hermit, Bruno, finds them and moves Anna to the back of a truck, but he is spotted by Sheriff Bronson while carrying Danny, and the moment ends with Anna’s truck slipping away, separating the siblings.
Nine years pass, and Danny drifts through multiple foster homes, repeatedly running away. When his latest escape is thwarted, his social worker places him at an orphanage run by Lindsay Brown. It’s there that he is reunited with Anna, who comes to his aid when an older boy named Xander Xander targets her. The twins share a deep, instinctive bond that manifests as identical odd mannerisms, even though they don’t yet understand what links them. As they grow closer, their latent powers begin to surface more clearly, revealing that they are not just siblings but twins connected by something extraordinary.
Their abilities catch the eye of Edward Bolt, a local magnate intent on developing Witch Mountain. Bolt brings the twins into his orbit, and Danny feels a sense of safety with the new home, while Anna grows wary. Bolt’s plans soon come into play: he intends to exploit the twins’ power to blast open Witch Mountain without explosives so he can access valuable rock material hidden within. Waldo Fudd, a visitor who also shares their gifts, warns that these powers come from a world where everyone has a twin, and that the twins were separated across Earth by quarrels that many of their kin forgot. Waldo’s mission becomes clear—reunite all the twins and return them to their home world, where they belong—though his motives are complicated and personal.
Zoe, following clues Waldo leaves, confronts him with questions about the twins’ fates. Waldo briefly dismisses her, yet offers enough hints to guide her search. Bolt’s manipulation grows riskier as he tries to command the twins to serve his plan, and Anna telepathically warns Danny of the danger, a warning that leads Bolt to seize Anna and hold her hostage to force Danny’s compliance. The escape comes with help from an unexpected ally: Xander, who turns from a personal rival to a reluctant helper and helps the twins flee to Waldo’s shop on a horse that Danny communicates with.
As suspicions mount, Lindsay Brown grows dubious of Bolt’s intentions, especially as police start closing in on the children’s whereabouts. With Zoe and Bruno by their side, the twins flee again, making a daring escape to Witch Mountain. There, Waldo and the other reunited twins gather, awaiting Anna and Danny so they can all return home together. The final arrivals—Bruno and Luthor—join the lineup of twins ready to cross back to their own world using Waldo’s network of power.
In a climactic burst of unity, Waldo and the twins on their home world combine their abilities, sending the entire group back home in paired arrivals, with Anna and Danny bringing up the rear to seal the gate between worlds. Waldo’s parting quip—about waiting for the next group of visitors—feels almost casual, but Zoe’s vow to tell their story anchors the tale: Witch Mountain isn’t haunted in the traditional sense; it simply glows with light. The journey ends with a hopeful note that some bonds are meant to endure beyond Earth, and that the shared power of twins can bridge worlds.
