City of Ember (2008) is a science fiction adventure film directed by Gil Kenan, based on the novel by Jeanne DuPrau. Set in a post-apocalyptic world, the film follows the story of a city called Ember, which was built underground to protect humanity from a devastating disaster. The city relies on a vast system of generators to provide light and power, but as the years go by, the generators begin to fail, and the once-bright city is slowly descending into darkness.

The story centers around two young protagonists, Doon Harrow (Harry Treadaway) and Lina Mayfleet (Saoirse Ronan), who are determined to find a way to save Ember. Doon, a young engineer, is assigned to work in the city’s underground power plant, where he discovers that the generator is on the verge of breaking down completely. Meanwhile, Lina, an aspiring messenger, stumbles upon an old box containing a set of mysterious instructions that she believes can lead to the city’s salvation.

As the city begins to plunge into total darkness, Doon and Lina work together to decipher the instructions and find a way out of Ember. Along the way, they uncover the city’s secrets and confront the corrupt leaders who have been keeping the truth hidden from the citizens.

The film explores themes of hope, resourcefulness, and the importance of preserving the environment, as the young heroes race against time to escape their dying city and find a way to restore light and life to their world.