Jake Sully and his family, now parents to four children, leave their forest home to protect the Omaticaya clan from returning human invaders led by a resurrected Colonel Quaritch. Taking refuge with the ocean-dwelling Metkayina clan, the family adapts to a new life, with the children forming deep bonds with the sea creatures, specifically the Tulkun. When Quaritch's violence forces a confrontation, the Sullys fight back, ultimately losing their eldest son, Neteyam, in a brutal battle. Despite this, they find a new home with the Metkayina, with Jake pledging to fight the RDA from the reef.