PLOT SUMMARY:  In the future, the society of Metropolis is divided in two social classes: the workers, who live in the underground below the machines level, and the dominant classes that lives in the surface. The workers are controlled by their leader Maria, who wants to find a mediator between the upper class lords and the workers, since she believes that a heart would be necessary between brains and muscles. Maria meets Freder Fredersen, the son of the Lord of Metropolis Johhan Fredersen, in a meeting of the workers, and they fall in love for each other. Meanwhile, Johhan decides that the workers are no longer necessary for Metropolis, and uses a robot pretending to be Maria to promote a revolution of the working class and eliminate them.