Eddie Murphy stars as shy Dr. Sherman Klump, a kind, brilliant, 'calorifically challenged' genetic professor. When beautiful Carla Purty joins the university faculty, Sherman grows desperate to whittle his 400-pound frame down to size and win her heart. So, with one swig of his experimental fat-reducing serum, Sherman becomes 'Buddy Love', a fast-talking, pumped-up , plumped down Don Juan.

In order to get back into the good graces with his wife with whom he has had a misunderstanding, a young chemistry professor concocts a wild story that he is an undercover FBI agent. To help him with his story he enlists the aid of a friend who is a TV writer. The wife swallows the story and the film's climax takes place in the sub-basements of the Empire State Building. The professor and his friend, believing themselves prisoners on an enemy submarine, patriotically try to scuttle the vessel and succeed only in rocking the building.

A certain professor of chemistry discovers two substances that, combined, make it possible to contravene the laws of gravity, a discovery that will have unexpected consequences for him.

L. M. Guerra, Knight of the University of Oxford; he tries to save our world, spreading the secrets that have been revealed to him.