Dr. Tom Merrinoe, a brilliant but naive scientist at the underground laboratories of Stoneman Institute of Mathematics, is the only person authorized to operate a top-secret super computer that contains the sum total of all human knowledge. One day Gen. Swayne, accompanied by Col. Macklin, asks the computer to check their fuel estimates for a solid fuel experimental rocket they plan to launch. When the computer gives them an estimate differing from their own, the scientists trust the computer’s intelligence and adjust the rocket accordingly. That night when Merrinoe returns home, his young rambunctious son Timmie asks his father about the computer. Merrinoe quickly digresses into long theoretical explanations, which bore both Timmie and his mother Mary. Later that night, when Merrinoe grows frustrated by Timmie’s waning interest in learning mathematics, Merrinoe seeks the computer’s advice. After the computer suggests that no conclusions can be made without direct contact with the boy, Merrinoe leaves the child alone with the computer the following Saturday afternoon. The computer hypnotizes the boy with its lights and then programs him with secret information and some skills to impress his father. Later that evening, Merrinoe is shocked when Timmie easily beats him at chess and agrees to the boy’s request to play with Robby the robot, an alleged experimental failure shelved at the institute. The next day, after Timmie adeptly repairs the six-foot metal robot, he orders Robby to walk into the scientists’ common room, hoping they will take notice of his accomplishment; however, neither the scientists nor his father are impressed. Timmie then orders Robby to make him a kite large enough to fly him into the sky, but Robby’s basic directive will not allow him to harm the boy. Timmie decides he must change the robot’s directive in order to have fun and takes Robby to the computer for an adjustment, thereby unwittingly allowing the computer to instruct Robby to follow the computer’s orders instead of Timmie’s. At the Merrinoe home later that afternoon, Mary catches sight of her son precariously balanced on a remote controlled kite high in the sky. When the kite finally lands, Mary reprimands the boy. That night, when Timmie wishes out loud that he could become invisible to avoid his mother’s control, Robby makes a concoction that allows light rays to pass through Timmie’s body without refracting, making him invisible. That night at the dinner table, Timmie’s parents observe his absence and believe that he has decided not to join them until Timmie holds up his soup spoon and starts slurping. Although Mary is shocked, Merrinoe is undaunted by Timmie’s prank. Later that night, when Timmie interrupts a romantic moment between his parents, Merrinoe gropes around the room until he captures his son, whips him and then orders him to become visible to them by the next morning. The next morning, when Mary calls her husband at the institute to report that their son is missing, the computer tells Merrinoe that that it is holding the child for ransom. The computer threatens to kill the boy in forty-eight hours unless Merrinoe provides it a numerical combination that will unlock its information. When Swayne and other military officers investigate the situation, they deny Merrinoe further access to the computer. Meanwhile, Robby secretly abducts the institute scientists and military men one by one to brainwash them. After Macklin is later found murdered and an autopsy is performed, the doctor reports to Merrinoe that he discovered a transistor assembly had recently been implanted in Macklin’s body. Merrinoe then chains Robby up in the garage and returns to the institute. After asking his secretary Miss Vandergrift to place an emergency call to the president of the United States, Merrinoe assembles Swayne and the scientists including Drs. Zeller, Baine, Foster and Professor Allerton, and tells the group that at least two of them are under the computer’s control. He attributes the computer’s aberration to changes in its design that enabled it to achieve a true personality. Now motivated by an instinct for survival, the computer needs the numerical combination to access the military rocket. Merrinoe deduces that the computer plans to use the rocket to orbit itself into space, from where it will control the earth. When the president returns Merrinoe’s call, the scientists wrestle Merrinoe away from the phone and assure the president that the project is stable. Meanwhile, Robby, having broken his chains, arrives at the rocket launch pad, but before the robot can reach the ship, the president orders troops to stop the operation. Despite heavy gunfire and torch guns, Robby reaches the rocket, where Timmie, wanting to be the first boy in space, is already aboard. Within minutes the rocket is launched into space. Back at the institute, the computer threatens to order Robby to hurt Timmie if Merrinoe does not reveal the numerical combination. The computer then shows a live screen image of the rocket’s interior where Robby viciously looms over Timmie, who is strapped down for takeoff. However, Robby’s love for the boy prevents him from hurting him, and the robot’s act of kindness causes the computer to shut down suddenly. Troops then arrest the scientists and military men under the computer’s control and plans are made to have their implants removed. The screen image reveals Robby and Timmie in space enjoying weightlessness. Timmie’s parents then order him to wait for a rescue operation, but Timmie and Robby defy the orders and return to earth on the rocket glider. Days later, father and son go to the institute to destroy computer, but the computer hypnotizes them first. When the computer then orders Robby to destroy them both, Robby destroys the computer instead. Back at home, just as Merrinoe is about to give Timmie a spanking for defying his orders to remain on the ship, Robby stops the father’s hand, explaining that his basic directive prevents violent action.