Neverwhere (1996)

Richard Mayhew's mundane existence in London is disrupted when he saves an injured girl named Door, thrusting him into the surreal realm of London Below. Now on the run from the sinister duo, Messrs. Croup and Vandemar, Richard and Door seek the enigmatic Angel Islington, who holds the key to unraveling the mystery of Door's family's murder. With the assistance of the cunning Marquis de Carabas and the fierce Hunter, they navigate a perilous journey, where Richard hopes to reclaim his former life while uncovering dark secrets along the way.