It's 1967, and Howard Schmear is on his way to make a fresh start for himself as a hippie in San Francisco, when he crashes his VW bus on a country road near a small town in dairy-rich Wisconsin. Penniless and desperate to get his vehicle fixed, Howard has no choice but to earn money working for the man who caused the accident, a fourth generation butter farmer named Melvin. But when Howard discovers that margarine - America's favorite new condiment - is illegal in Melvin's dairy-dependent hometown of Butterfield, and demand for the illicit substance is on the rise, he realizes he's just stumbled onto his literal and figurative cash cow - and Melvin, with his neighborly ways and butter delivery service, is the perfect unwitting accomplice!