Alexander Key's popular pre-teen novel concerns two orphaned siblings with supernatural powers taken in by a nefarious millionaire (named Aristotle Bolt!) who wants to exploit their magical abilities for personal gain. Top-notch Walt Disney adventure for families has natural, non-precocious performances from young Ike Eisenmann and Kim Richards as the gifted kids, and their friendship with good-hearted traveler Eddie Albert is sweet but not sticky. The eerie flashbacks to the youngsters' early beginnings are well-captured by director John Hough, who is otherwise forced (perhaps for budgetary reasons) to skimp on genuine atmosphere in place of an elongated chase. Too bad the finale replaces emotion with effects, as these characters are quite remarkable. Followed by a fairly wan sequel, 1978's "Return From Witch Mountain", in which the special effects became the whole show. **1/2 from ****