Written by Martin and George Gipe the film is a broad comedy. Martin plays Dr. Michael Hfuhruhurr, a pioneering neurosurgeon with a cruel and unfaithful new wife, Dolores Benedict (Kathleen Turner).
Spoiler warning: Plot or ending details follow.
Hfuhruhurr saves the life of Benedict, who was injured in a car accident. As she recovers Hfuhruhurr falls in love with her and they marry. She is only interested in his wealth. On a honeymoon/business trip to a medical conference in Vienna, a city living in fear of the serial "Elevator Killer", Hfuhruhurr leaves his wife and meets mad scientist Dr. Alfred Necessiter (David Warner) who has created a radical new technique, storing living brains in liquid-filled jars.
Hfuhruhurr discovers he can communicate telepathically with one of the brains, that of Ann Uumellmahaye (voiced by Sissy Spacek). The two immediately fall in love. The confluence of a spate of random murders and the possibility of brain transplantation causes Hfuhruhurr to speculate about how he might improve his lot in life...
A man whose brain was separated down the middle to treat epilepsy is helping scientists understand how the organ works.
The advantage of separating the two halves is that scientists can then ask each side to carry out different tasks - with no assistance from the other side.
The left hemisphere is always considered to be the part of the brain which develops some particularly human skills, such as language.