Answer the following question: Extract the answer to the following question from the movie plot. If the question isn't answerable, please output "Can't answer". Question: Who is the city's master? Title: Metropolis Movie plot: The film is set in the year 2026, in the extraordinary Gothic skyscrapers of a corporate city-state, the Metropolis of the title. Society has been divided into two rigid groups: one of planners or thinkers, who live in luxury on the surface of Earth, and another of workers who live underground toiling to sustain the lives of the privileged up above. The city is run by Johann 'Joh' Fredersen (Alfred Abel).The beautiful and evangelical figure Maria (Brigitte Helm) takes up the cause of the workers. She advises the desperate workers not to start a revolution, and instead wait for the arrival of "The Mediator", who, she says, will unite the two halves of society. The son of Fredersen, Freder (Gustav Frohlich), becomes infatuated with Maria, and follows her down into the working underworld. In the underworld, he experiences firsthand the toiling lifestyle of the workers, and observes the casual attitude of their employers (he is disgusted after seeing an explosion at the "M-Machine", when the employers bring in new workers to keep the machine running before taking care of the men wounded or killed in the accident). Shocked at the workers' living conditions, he joins her cause.Meanwhile his father Fredersen consults with the scientist Rotwang (Rudolf Klein-Rogge), an old companion and rival. Fredersen learns that the papers found with dead workers are plans of the catacombs and witnesses a speech by Maria. He also learns that Rotwang has built a robotic gynoid. Rotwang wants to give the robot the appearance of Hel, his former lover who left him for Fredersen and died giving birth to Freder. Fredersen persuades him to give the robot Maria's appearance, as he wants to use the robot to tighten his control over the workers. Rotwang complies out of ulterior motives: he knows of Freder's and Maria's love and wants to use the robot to deprive Fredersen of his son.The real Maria is imprisoned in Rotwang's house in Metropolis, while the robot Maria is first showcast as an exotic dancer in the upper city's Yoshiwara...
Answer:
Johann 'Joh' Fredersen