When an unspecified global catastrophe looms, an underground city known as Ember is constructed to shelter a large group of survivors. In addition, a small metal box intended for a future generation of Emberites is timed to open after 200 years. This box is entrusted to first Mayor of the City of Ember, and each Mayor passes it on to their successor. When the seventh Mayor dies suddenly, the box is placed in a closet and forgotten about. The box opens by itself at the allotted time but goes unnoticed. Several decades later, Ember's generator begins to fail, and food, medicine, and other necessities are in dangerously short supply. At a rite of passage event for all graduating students of Ember City School, Mayor Cole stands before the students as their adult occupations are assigned by lottery. Doon Harrow, the son of inventor and repairman Loris Harrow, is assigned "Messenger" while his classmate Lina Mayfleet is assigned "Pipeworks Laborer". Shortly afterwards, the two secretly exchange assignments and Doon is apprenticed to the elderly technician Sul. At home, Lina, a descendant of the seventh Mayor, finds the opened box and enlists Doon's help to decipher its contents. Gradually, they learn that it contains a set of instructions and directions for an exit from the city in the Pipeworks, left by the city's builders. Later, after evading a gigantic star-nosed mole, they also discover that Mayor Cole has been hoarding food in a secret vault for his own benefit while the people go hungry. When Lina attempts to report this, the Mayor captures her and tries to confiscate the box, but she escapes during a blackout. Now fugitives from the Mayor's police, Lina and Doon, accompanied by Lina's baby sister, Poppy, use the instructions and assistance from Sul to flee the city via a subterranean river. When the repercussions of their actions trigger a panic in Ember, the Mayor locks himself in his vault, only to be devoured by the giant mole. Lina, Doon, and Poppy eventually reach the Earth's surface, where they witness a sunrise for the first time. They also locate Ember through a hole in the ground, too far for them to call to anyone. Before they explore, Lina and Doon write a letter with instructions on how to get out of the city, which they tie to a rock and throw down to the city. The rock lands by Loris' feet, who picks it up.

A massive meteor shower destroys the orbiting Space Shuttle Atlantis before entering the atmosphere and bombarding Boston, Philadelphia, Moncton, Halifax, Newfoundland and New York City, the latter being extensively damaged. The meteors were pushed out of the asteroid belt by a collision from a rogue comet the size of Texas and NASA learns it will impact Earth in 18 days, wiping out all life on the planet. NASA devises a plan to drill a deep hole into the asteroid, into which they will insert and detonate a nuclear bomb to split it into two pieces that will each pass to one side of Earth. They recruit Harry Stamper, a third-generation oil driller and owner of an oil drilling company, who agrees to help but on the condition that he bring in his own team to do the drilling. He picks his best employees for the job: Chick Chapple, his best friend and right-hand man; geologists Rockhound and Oscar Choice; and drillers Bear Curlene, Max Lennert, Freddie Noonan, and A. J. Frost (who has been dating Harry's daughter Grace despite Harry's objections). Over twelve days, they are trained to become astronauts with astronaut Willie Sharp, who will pilot Freedom — one of the two super shuttles to fly to the asteroid, the other being the Independence. Before leaving, Chick apologizes to his ex-wife for wronging her and sees his son—who is unaware of his parentage—and Grace accepts A.J.'s marriage proposal, much to Harry's reluctant dismay; she later has her father promise to return home safe and with her fiancé. Following the destruction of Shanghai by another meteor strike, word of the asteroid becomes public to the world. Both shuttles take off without incident and dock with a Russian space station to take on fuel, but a broken pipeline sets the fuel pod ablaze. A.J. and Roscosmos cosmonaut Lev Andropov narrowly manage to board Independence before the space station is obliterated. Approaching the asteroid, Independence is damaged by debris and crashes, killing Oscar, Freddie, and the rest of the crew. The survivors—Lev, Bear, and A.J.—embark in the shuttle's mobile driller "Armadillo" to find the Freedom crew, which landed 26 miles (42 km) from its intended landing/drilling site. When the drilling goes slower than predicted, Sharp reports to Mission Control that it is unlikely they will reach the depth necessary to split the asteroid before "Zero Barrier", the point after which splitting the rock will not prevent the pieces from hitting and destroying Earth. The president of the United States decides to remotely detonate the bomb from Earth immediately, not understanding this will cause total mission failure. Sharp and Harry have a vicious argument, but agree to defuse the bomb and work together after Harry promises Sharp that he will accomplish the mission. They make up on lost drilling time, but a missed gas pocket causes their Armadillo and Max to be blown into space. Just as Harry, NASA, and the world believe the mission to be a failure, and another meteor destroys Paris, A.J. and the others arrive in the second Armadillo. A.J. successfully finishes the drilling, but a rock storm kills munitions officer Gruber and damages the bomb's remote detonator, forcing someone to stay behind and manually detonate it. They draw straws; A.J. is given the responsibility. Harry takes him down to the asteroid's surface, only to disconnect A.J.'s air hose and force him back into the shuttle's air lock, before telling A.J. that he is the son Harry never had, and he would be proud to have him marry Grace. From within the Armadillo, Harry tearfully gives Grace his blessing to marry A.J., and Grace says she is proud to be his daughter. After overcoming a malfunction, Freedom takes off, and just before Zero Barrier, Harry manages to detonate the bomb and saves the planet, sacrificing his life in the process. The astronauts land on Earth safely. A.J. and Grace are reunited, and Chick reconciles with his ex-wife and estranged son. During the credits, A.J. and Grace are married, with the portraits of Harry, Oscar, Max, and Freddie present in memoriam.

Gao Jianxiang (Aaron Kwok) is a Malaysian Chinese corrupt policeman in Kuala Lumpur. He kills a pedestrian on the way to his mother's funeral. To escape responsibility, in a moment of desperation, Gao hides the body in his trunk, and then his own mother's coffin. He thinks that his life could return to calmness, but unexpectedly, the pedestrian who was killed by him was a wanted man, and Gao is also eyed by the police. Shortly afterwards, a mysterious phone call is made to him. He realizes that all this is a conspiracy and he is already in deep trouble.

Amy, an 11-year-old girl from Senegal, lives with her mother Mariam and two younger brothers, one of them named Ishmael, in an apartment in one of Paris' poorest neighbourhoods. She is angered by her polygynous father, who is preparing to return with a second wife. She is also bored with Islamic culture that her aunt seeks to impose on her. Amy is fascinated by her disobedient neighbour Angelica's pre-teen twerking clique, the Cuties, which is in stark contrast to Mariam's Muslim customs. They do not hesitate to adopt revealing outfits against their older rivals, the Sweety Swags. In the quest for online recognition, Amy decides to incorporate suggestive dance moves into the choreography. After getting pantsed for fighting with Sweety Swags, she steals her cousin’s phone and sends a photo of her vulva online to a social network in an attempt to look mature, backfiring heavily with her being ostracised, also causing a rift between her and the Cuties who kick her out, replaced with former member Yasmine. Her mother also confronts her for committing such indecency. She and her aunt try performing an exorcism on Amy, but it fails. While her father's wedding day corresponds to the finale at the Parc de la Villette, she is determined to dance with them, and sneaks out of the house. She pushes Yasmine into a canal, so the Cuties have no choice but to allow her to dance with them. The highly suggestive dance routine polarizes audiences. Suddenly thinking about her mother during the routine, Amy bursts into tears and leaves before their performance ends. Upon her return, she runs into her aunt, who blames her for her outfit and recent attitude. Amy's mother intervenes by telling her to leave her daughter alone and then hugs her to reassure her. Amy implores her mother to not attend the wedding. Amy's mother permits her not to go, but states that she herself must go to fulfill her duty as a wife. In the end, Amy abandons both the traditional wedding dress and her provocative dancer's outfit, living a normal youth lifestyle.