Research chemist Barnaby Fulton works on a fountain of youth pill for a chemical company. One of the labs chimps gets loose in the laboratory and mixes chemicals, but then pours the mix into the water cooler. When trying one of his own samples, washed down with water from the cooler, Fulton begins to act just like a twenty-year-old and believes his potion is working. Soon his wife and boss are also behaving like children.
An airline pilot pursues a live-in babysitter at his hotel and gradually realizes she is not as stable as perhaps she should be.
Virginia Cunningham is confused upon finding herself in a mental hospital, with no memory of her arrival at the institution. Tormented by delusions and unable to even recognize her husband, Robert, she is treated by Dr. Mark Kik, who is determined to get to the root of her mental illness. As her treatment progresses, flashbacks depict events in Virginia's life that may have contributed to her instability.
