Tony and Tia are brother and sister with powers that frighten the authorities. Because they have no family, they are sent an orphanage where a man by the name of Lucas Deranian, pretending he's a long lost uncle, offers to adopt them. Rather than go with him, Tony and Tia run away, all the while searching for a clue to their identities. With the help of a Father O'Day from St. Paul's Mission, Tony and Tia try to reach Witch Mountain where (they think) other people like them live. In the meantime, Deranian still tries to get his hands on them, and does all he can to prevent Tony and Tia from reaching their destination
