The planet Krypton is destabilized from mining of the planetary core. Jor-El, chief advisor to Krypton’s supreme council, recommends that the council give him control of the genetics codex. Before any action can be taken, soldiers led by General Zod, an old friend of Jor-El’s, launch an uprising and arrest the councilors. Realizing that Krypton is doomed, Jor-El steals the genetic codex sought by Zod and infuses them into the DNA of his infant son, Kal-El, the first naturally born Kryptonian child in centuries. Zod kills Jor-El, who sacrifices himself to allow his son to escape on a preprogrammed spacecraft after his wife Lara-El launches it. The council quashes Zod’s rebellion, and the rebels are sentenced to exile in the Phantom Zone after being convicted of treason. Krypton explodes soon after.
Following Jor-El’s coordinates, the ship crash lands on Earth in Kansas. A childless couple, Jonathan and Martha Kent, find Kal-El and raise him as their own, naming him Clark. Clark eventually becomes an isolated young man as a result of developing superhuman powers which he tries to hide from others. He learns his true origins from Jonathan, who urges him to keep his powers hidden. Several years later, Jonathan dies in a tornado while refusing to let Clark rescue him, as that might reveal Clark to the world before he’s ready. Burdened with guilt and looking for a new purpose in his life, Clark leaves to travel the world for several years under various aliases.
Daily Planet reporter Lois Lane receives an assignment to investigate the discovery of a Kryptonian scout ship in the Canadian Arctic. Having gained work at the discovery site, Clark enters the ship and activates its central computer using a key left by Jor-El, which allows him to communicate with an artificial intelligence modeled after his father. The AI explains that Clark was sent to Earth to guide its people, and presents him with a Kryptonian uniform bearing his family’s symbol. While following Clark, Lois inadvertently triggers the ship’s security system. Clark uses his powers to rescue Lois before wearing the uniform and testing his flying abilities. Unable to convince supervisor Perry White to publish an article on the incident, Lois tracks down Clark back to his family home in Kansas, intent on finding the truth. She tries to persuade Clark to let her reveal his story, but decides to drop it after hearing of Jonathan Kent’s sacrifice, and keeps Clark’s identity safe.
Escaping the Phantom Zone, Zod and his crew intercept a transmission from the scout vessel and travel to Earth. Deducing that Kal-El is nearby, they broadcast a global address demanding that he surrender or risk war. Without revealing his identity and wearing the Kryptonian uniform, Clark meets with the United States Air Force and agrees to comply, with Lois joining him as a hostage. Zod reveals that he possesses several terraforming devices, the largest called a World Engine, which he salvaged from Kryptonian outposts, which he intends to use to transform Earth into a new Krypton. His science officer, Jax-Ur, extracts information from Clark’s genes to create Kryptonian colonists who will annihilate humanity and build a society based on Zod’s ideals of genetic purity.
Using the Jor-El AI to take over the ship, Clark and Lois flee and warn the U.S. military of Zod’s plan, resulting in an explosive confrontation between Clark and Zod’s troops, just as Zod orders an invasion. Zod deploys the World Engine from the Kryptonian ship, which touches down in the Indian Ocean and begins firing a beam through the planet towards the ship, severely damaging the city of Metropolis, and initiating the terraforming strategy. Clark destroys the World Engine while the military launches a suicide attack, sending Zod’s troops back to the Phantom Zone. With the ship destroyed and Krypton’s only hope of revival gone, Zod vows to destroy the Earth and its inhabitants out of revenge. The two Kryptonians engage in a lengthy battle across Metropolis, which concludes when Clark is forced to kill Zod as he attacks a cornered family in a train station.
Clark adopts a separate public identity with the military codename “Superman” and persuades the government to let him act independently, so long as he does not turn against humanity. To allow access to dangerous situations without attracting attention, he covertly maintains his civilian identity and takes a job as a freelance reporter for the Daily Planet.