It's 1940 and Europe is at war. Fritz Duquesne, a German spy straight from the history books, schemes to steal America's nuclear secrets and hatches a plan to kidnap Albert Einstein. Enraged by Charlie Chaplin's mockery in The Great Dictator, Adolf Hitler dispatches an SS assassin to silence the man who weaponized laughter. Nazi agents, American gangsters, and FBI operatives converge aboard the Santa Fe Super Chief, pulling Einstein and Chaplin into a deadly showdown as the train races from Chicago to Los Angeles.