In the 23rd century, a catastrophic interplanetary war known as "The Fall" aka "The Great War" has left Earth devastated. 300 years later in 2563, while scouting the junkyard metropolis of Iron City, scientist Dr. Dyson Ido discovers a disembodied female cyborg with a fully intact human brain. Ido attaches a cyborg body to the brain, who does not have any recollections of her past, and names her "Alita" after his deceased daughter, for whom he originally built the body. As Alita wakes to learn about this unfamiliar world, she meets and befriends Hugo, a charismatic young man who passionately dreams of moving to the wealthy sky city of Zalem someday. Hugo also introduces her to the competitive sport of Motorball, a battle royale race wherein cyborg gladiators fight over a ball and win by bringing it to the finish line. Secretly, however, Hugo generates funds meant to buy his way into Zalem by mugging cyborgs and stealing their parts for Vector, an entrepreneur who owns the Motorball tournament, who in turn aims to use the parts to put together his own unbeatable champion.