A group of scientists takes Simon, a psychology professor, as a test person for a brainwash experiment. After that they try to convince him that he is a being from another planet.
The Institute for Advanced Concepts, headed by Dr. Carl Becker along with four fellow scientists, has unlimited resources secretly funded by the highest powers to conduct unfettered research to control and manipulate the world in all aspects. Their next brainchild of a project is to brainwash someone in believing that he is an alien and unleash him into the world to see what happens. That brainwashing includes making him believe that his "mother" produced him in the form of a human, much like one would produce a toaster. Who they choose is Psychology professor Dr. Simon Mendelssohn, partly because he was a foundling whose true origins no one can question. They are able to lure him to the Institute under the guise of being able to conduct his own research, his fascination with but little understanding of sensory deprivation which they are further able to capitalize on in the brainwashing process. To further ensure that Simon complies, they plan on using their seductive female "associate", Dr. Cynthia Mallory, to act as a Juliet operative. Unleashing Simon the alien into the world, they will have to contend with his casual girlfriend, Lisa, a Music professor at the same New York City college, she who may have her own ways of proving that Simon is not the alien he and they assert he is.—Huggo
The Institute for Advanced Concepts is a think tank composed of five scientists with an unlimited budget and a propensity for fabricating national hysterias. The five hatch a plan to trick a man into thinking he is of extraterrestrial origin through brainwashing and, using their computer to conduct a national search, settle on a psychology professor named Simon Mendelssohn (Alan Arkin), who was abandoned at birth and is trying to perform an experiment with an isolation tank. At the Institute, Simon is submerged in an isolation tank of their own and, after an extended time, emerges in a weakened mental state that causes him to reenact the entire history of evolution of life on Earth from a single-celled organism to a modern man. While Simon is in this state, the scientists plant a hypnotic suggestion that his mother is an alien spaceship and that he was made as a machine rather than being born naturally. The five then put their plan to create a mass hysteria into action by broadcasting Simon's ramblings, which include a number of proposals to reform American culture. When they decide Simon has become too dangerous as a result of his newfound celebrity status, they call in the military to kill him, but his girlfriend Lisa (Judy Graubart) comes to his rescue.
As the couple goes on the run, Lisa tries to remind Simon that he is an ordinary human. Along the way, they encounter a commune that worships a television, which they call the "magic box," and have no concept of disliking anything they watch. The founder of the commune (Adolph Green) used to work for the American Broadcasting Company and so has a truck with a high-powered TV transmitter. The military soon locates the origins of Simon's hijacked TV signals, forcing the couple to flee once again. In doing so, Lisa finally convinces Simon that he is human when she tells him she is pregnant with his child.
Dr. Becker (Austin Pendleton), head of the Institute, blames the release of a gas that takes a hundred points off the IQs of the other scientists on Simon. As the four are acting childish, Becker and the military commander (Fred Gwynne) arrange a rocket launch to get rid of Simon, supposedly by sending him home to his planet but really by just launching him into space without a destination. Simon calls and turns himself in, and Becker, thinking he is fooled, accompanies him to the rocket. But Simon overpowers Becker, straps him into the rocket seat and escapes in a NASA uniform as Becker is launched into space.
Simon and Lisa are last seen having settled down in Canada with their child, where they plan to live in peace and obscurity despite the American media continuing to search for Simon. A radio broadcast informs Lisa that Simon has just won the Nobel Peace Prize for his suggestions in his broadcasts to improve American life, such as prohibiting anyone from replacing towels with blow-drying machines in public restrooms.
