One thousand years after cataclysmic events forced humanity's escape from Earth, they re-established society on the planet Nova Prime. Abandoned, Earth continued to flourish on its own. One thousand years after the departure from Earth, the Ranger Corps, a peace keeping organization established shortly after colonization of Nova Prime, is led by the legendary General Cypher Raige (Will Smith), a wise but cold and emotionless father. His teenage son, Kitai (Jaden Smith), is a recruit of the Ranger Corps, but his knack for mischief frustrates Cypher. Cypher takes Kitai on a mission to Earth.
12-year-old Dre Parker (Jaden Smith) could've been the most popular kid in Detroit, but his mother's (Taraji P. Henson) latest career move has landed him in China. Dre immediately falls for his classmate Mei Ying—and the feeling is mutual—but cultural differences make such a friendship impossible. Even worse, Dre's feelings make an enemy of the class bully, Cheng. In the land of kung fu, Dre knows only a little karate, and Cheng puts "the karate kid" on the floor with ease. With no friends in a strange land, Dre has nowhere to turn but maintenance man Mr.
Renowned scientist Dr. Helen Benson (Jennifer Connelly) finds herself face to face with an alien called Klaatu (Keanu Reeves), who travels across the universe to warn of an impending global crisis.