"The Invisible Boy" is a mixture of lighthearted playfulness and menacing evil. In 1957, ten-year-old Timmie Merrinoe (Richard Eyer) seems only to want a playmate. After a peculiar encounter with a supercomputer operated by his father's research lab, he is mysteriously invested with superior intelligence, and reassembles a robot that his father and other scientists had been ready to discard as irreparable junk. (It is explained that a vanished scientist claimed to have developed a time machine and retrieved the robot from the future -- a photograph on the wall depicts the return to Earth of the space cruiser from "Forbidden Planet," and the arrival of "Robbie the Robot.") No one pays much attention to the robot after Timmie gets it operating again, until Timmie's mother becomes angry when her son is taken aloft by a huge powered kite that Robby has built at Timmie's urging (once Timmie, prompted by the supercomputer, has disabled Robbie's programming to never endanger a human).