Although the first science fiction film is generally agreed to be Georges Méliès' A Trip To The Moon (1902), Metropolis (1926) is the first feature length outing of the genre. It was also the most expensive feature film yet made in Europe, and marked a new vision of what film could be as a creative medium. It contains mindboggling spectacle - especially as it was envisioned in the dark days of post WW1 Germany - as well as searing political and social comment on the nature of the class struggle and humans' relationship to machines. Its influence has been profound and far reaching: Hitler and Goebbels were big fans, and asked Lang to make Nazi propaganda films when they gained power in 1933. Lang left Germany immediately. Its visual scope is reflected most directly in Blade Runner (1982), Dark City (1998), The Fifth Element (1997) and AI: Artificial Intelligence (2001).
Set in 2026, Metropolis follows the fortunes of Freder Frederson, one of the privileged sector of humanity who get to frolic in gardens whilst their fellow citizens are slaving away in a huge underground zone known as the Lower City.
Those living in the Lower City lack any kind of freedom and are unable to act upon their individual dreams as they are forced into hard labor in the factories. The citizens can't choose to pursue personal ambitions such as a nursing career (for instance) or the life of an artist, instead, they are doomed to the dull, repetitive and exhausting life of a factory worker. This is in stark contrast to the pleasant existence led by citizens in the airy offices and gardens of the Upper City. The class divide sets up the essential conflict of the movie, and drives the characters' struggle to attain independence and freedom in a unified Metropolis.
Freder is the son of John Frederson, the autocratic ruler of the city, and has lived a life without care. His idyllic existence is threatened one day when Maria, beautiful Lower City dweller, appears in his Upper City garden, with ragamuffin children in tow, to tell the startled aristocrats that they are all brothers. Although she is quickly packed off back to the squalor of the Lower City, her beauty has a strong impression on Freder, and he ventures down into the Lower City to find her.
What follows is a re-imagining of the class struggle, with the underground workers representing the hands of society and the Upper City dwellers with their penthouse offices representing the brain. Freder is horrified by conditions underground - he witnesses the deaths of many workers in an explosion. He tries to plead their cause with his father, who is more worried about a possible uprising. Frederson Senior is also involved with the construction of a robot woman along with the inventor Rotwang.
As the workers plot their uprising, Rotwang and Frederson Snr give their robot woman the physical form of Maria, having kidnapped the real thing. Robot Maria then precipitates social turnoil - by dancing naked for the aristocrats in the Yoshiwara, and by encouraging the workers to revolt. While the aristocrats shoot each other in duels over the love of the beautiful nude dancer, the workers abandon their children to go and smash machinery, thus flooding the Lower City. The real Maria escapes from the clutches of Rotwang and goes to rescue the children from drowning, whilst the workers burn the false Maria. Freder and Maria are reunited. As the Metropolis collapses around everyone's ears an alliance is declared between the rulers and the ruled: as the final title states "the mediator between brain and hands must be the heart", and Freder and Maria are seen as the symbols of a new age of unity.