Return From Witch Mountain(1978)
In this follow-up to ESCAPE TO WITCH MOUNTAIN, Tony (Ike Eisenmann) and Tia (Kim Richards) return to Earth for a vacation. However, that's cut short when egomaniacal Dr. Gannon (Christopher Lee) and his companion Letha (Bette Davis) discover Tony's powers, kidnap him, and attempt to use him to rule the world. Tia, meanwhile, finds herself running with a young gang who are consistently truant from school, and the group searches frantically for the missing Tony.
Followed by the TV-movie BEYOND WITCH MOUNTAIN.
This trailer was originally posted to YouTube by mearbhrach.