The central twist of "The Great Dictator" is the case of mistaken identity between the amnesiac Jewish barber and the dictator Adenoid Hynkel, both played by Chaplin. After Commander Schultz, a high-ranking officer whom the barber saved in World War I, falls out of favor with Hynkel, both he and the barber are sent to a concentration camp. They manage to escape, disguised in military uniforms.
Meanwhile, Hynkel, on a duck-hunting trip, falls into a river and is mistaken for the escaped barber and arrested by his own stormtroopers. The climax of the film occurs when the escaped barber, due to his uncanny resemblance to the dictator, is mistaken for Hynkel. He is whisked away to the capital of the newly-invaded neighboring country of Osterlich and is expected to deliver a victory speech to the nation and the world.
The film's most profound reveal is that instead of delivering a fascist tirade, the barber seizes the opportunity to speak from his heart. He delivers a passionate, six-minute monologue, not as the barber or as Hynkel, but seemingly as Chaplin himself. He denounces dictatorship, greed, and hate, and makes an impassioned plea for democracy, unity, and human kindness. He ends his speech with a direct message of hope to Hannah, who has escaped to Osterlich and is listening to the broadcast in a refugee camp. The hidden meaning that becomes clear is that the film's purpose was not just satire; it was a direct and urgent call to action. The entire narrative, with its comedic and dramatic elements, serves as a setup for this final, powerful rhetorical appeal to the conscience of the world.