Mafia hitman Tommy Spinelli is flying to San Diego with a bag that holds eight severed heads, which he's bringing to his superiors to prove that some troublesome rival mobsters are permanently out of the picture. When his bag gets accidentally switched at the airport, Tommy must track down his duffel bag and the 8 heads it contains.

A road warrior vigilante avenges his brother's death at the hands of a crazy motorist by using his souped-up pickup to apprehend drunken drivers and others who abuse their driving privileges.

An eccentric scientist in the Amazon jungle rejects his research assistant for being a woman, but as bulldozers threaten their work on a potential cancer cure, they learn to collaborate and begin to fall in love.

Before going on vacation, self-involved psychiatrist Dr. Leo Marvin has the misfortune of taking on a new patient: Bob Wiley. An exemplar of neediness and a compendium of phobias, Bob follows Marvin to his family's country house. Dr. Marvin tries to get him to leave; the trouble is, everyone loves Bob. As his oblivious patient makes himself at home, Dr. Marvin loses his professional composure and, before long, may be ready for the loony bin himself.