While on a cross-country train ride, overworked book editor George Caldwell (Gene Wilder) begins an unexpected romance with an enigmatic woman named Hilly Burns (Jill Clayburgh). His vacation is interrupted, however, when he witnesses a murder for which he is then accused. The true villains kidnap Hilly and eject Caldwell from the moving train. Desperate, Caldwell teams up with car thief Grover Muldoon (Richard Pryor), and together they must save Hilly while avoiding the police.