Metropolis is a 1925 novel by the German writer Thea von Harbou. The story is set in 2026 in a technologically advanced city, which is sustained by the existence of an underground society of labourers. The son of one of the city's founders falls in love with a girl from the underground society, as the two societies begin to clash due to the lack of a unifying force. The novel was the basis for Fritz Lang's 1927 film Metropolis.