Kim Richards

Tia and Tony are teenage sister and brother who possess extraordinary powers. They leave their safe refuge on Witch Mountain for a trip to Los Angeles. There, Tony is kidnapped by the evil Dr. Gannon and his spinster partner Letha. Tony is brainwashed into helping Gannon and Letha commit various crimes. It's up to Tia and a gang of juvenile delinquents to rescue Tony and prevent a major disaster.