Set more than a decade after the events of the first film, Jake Sully (Sam Worthington) and Neytiri (Zoe Saldana) are happily married. They're enjoying their peaceful lives in the forest and over the years, they joyfully welcome four children into their lives: Neteyam
(James Flatters), Lo'ak (Britain Dalton), Tuk (Trinity Jo-Li Bliss) and adopted teenage daughter, Kiri (Sigourney Weaver). The kids often hang out with Spider (Jack Champion), a human child orphaned by the war who was too small at the time to return to Earth.

But when the Sky People return, notably Colonel Miles Quaritch (Stephen Lang) who is looking to get even with Jake for what happened in the past, Jake finally decides that he, Neytiri and their four children must leave their forest life in order to survive.

After making the long journey across the vast oceans of Pandora, the Sullys arrive at the home of Metkayina clan, led by Ronal (Kate Winslet) and Tonowari (Cliff Curtis), who reluctantly allow them sanctuary in their reef village.