Lloyd Christmas (Jim Carrey) and Harry Dunne (Jeff Daniels) are two intellectually-challenged best friends who live together in a messy apartment. Lloyd works as a limo driver and immediately falls in love with Mary when he takes her to the airport. When Mary leaves a briefcase at the airport, Lloyd and Harry take it in order to return to her without knowing that Mary deliberately left it since it contain money for a ransom payment to save her kidnapped husband.