Avatar: Fire and Ash

Shortly after the death of Jake and Neytiri's eldest son Neteyam, the Sully family grieves amongst the Metkayina, with Neytiri developing a deeper hatred toward humans. After Spider's breathing mask runs out of power during his sleep, Jake and Neytiri decide he must return to the human scientist camp for his safety. The Sully family accompanies him on the trip aboard a fleet of flying merchant vessels.
The merchant convoy is ambushed by raiders of the Mangkwan, an aggressive Na'vi clan. Led by their matriarch Varang, the Mangkwan loot and set fire to the ships, killing many and scattering the Sully family. After Miles Quaritch captures Jake, the two work together to locate Spider. Meanwhile, Spider collapses when his mask loses power, motivating Jake's adopted daughter Kiri to spontaneously infuse his body with mycelia, which gives him the ability to breathe Pandora's air.
The Mangkwan capture Quaritch, Jake and the children, after which Quaritch teaches Varang how to use firearms. Kiri commands nearby flora to kill their guards, enabling everyone to escape. The human scientists Norm Spellman and Max Patel believe Spider's mycelia could be reverse engineered to allow other humans to breathe on Pandora. Kiri learns that she was born from Eywa, but is blocked from connecting with her. Quaritch offers guns and flamethrowers to the Mangkwan and convinces them to form an alliance, then begins an intimate relationship with Varang.
Kiri helps Spider explore his newfound ability to neurally connect with other organisms, and they share a kiss. Quaritch captures Spider and then arrives at the Metkayina village with the Mangkwan, demanding that Jake turn himself in. Jake surrenders to avoid bloodshed, and he and Spider are taken to the Resources Development Administration (RDA) base. Jake's son Lo'ak searches for Payakan ahead of a Tulkun congregation that will be targeted by RDA hunters. RDA biologist Ian Garvin urges the hunters to back down, but he is ignored.
Spider undergoes testing by RDA scientists, while Jake is scheduled to be executed. Neytiri infiltrates the RDA base, Spider manages to escape his cell, and Garvin frees Jake. After Jake, Neytiri and Spider escape, Jake regretfully prepares to kill Spider so the RDA cannot learn more about his breathing abilities. However, Jake cannot bring himself to kill him, and they embrace.
At the Metkayina village, the Tulkun council hear Jake's warning about an impending massacre, but decide not to change their pacifist ways. However, when Lo'ak brings Payakan and Ta'nok, both disfigured Tulkun hunting raid survivors, the Tulkun elders reconsider. Jake re-bonds with the apex predator Toruk and rallies the Na'vi clans to battle. When the RDA fleet arrives for the hunt, the Tulkun and Na'vi ambush them. However, Quaritch and the Mangkwan arrive and turn the tide in their favor. The Metkayina matriarch Ronal is wounded and dies in childbirth, with Neytiri delivering her baby daughter, Pril, before being captured.
With the help of Spider and Jake's daughter Tuk, Kiri finally communicates with Eywa and pleads for help. In answer, the Pandoran wildlife ambush the rest of the RDA forces, saving the cornered Tulkun. Varang tries to kill Neytiri, but is repelled by Kiri. Ta'nok kills the lead Tulkun hunter Mick Scorseby. Jake and Quaritch are thrown into a magnetic flux, which is destroying the remaining RDA vessels. As Jake and Quaritch fight, Spider falls off a floating rock, forcing them to work together to save him. When Neytiri and her children arrive, Quaritch throws himself off the rock.
After the battle, Spider and the Metkayina connect to the underwater spirit trees, where Spider meets all the deceased Na'vi. Kiri introduces Spider to her mother, Grace, and they initiate him into the Na'vi people.