Avatar: The Way of Water is the product of thirteen years of waiting, five years of active production, and one of the largest film budgets in cinema history. James Cameron began developing the sequel in 2010 and spent years building the production infrastructure necessary to execute his vision — specifically, the ability to shoot performance capture underwater, something no film had ever done at scale. Filming began in 2017, ran for three years, and was completed in September 2020. The film was released on December 16, 2022, with a runtime of 3 hours and 12 minutes — longer than Titanic's theatrical cut — and a budget estimated between $350 and $460 million, making it one of the most expensive films ever made. The gamble paid off: The Way of Water grossed $2.32 billion worldwide, becoming the highest-grossing film of 2022 and the third-highest-grossing film of all time, behind only Avatar (2009) and Avengers: Endgame. At the 95th Academy Awards it received four nominations: Best Picture, Best Visual Effects, Best Production Design, and Best Sound. The story picks up sixteen years after the first film, with Jake Sully (Sam Worthington) and Neytiri (Zoe Saldaña) raising a family of five children in the forests of Pandora before the return of the RDA forces them to seek refuge with the Metkayina, a reef-dwelling Na'vi clan whose culture, body shape, and relationship with the ocean are distinct from the forest Na'vi Jake has lived among. The film's central technical achievement — underwater performance capture executed in a giant tank where actors performed scenes in real water at depth — required the entire cast to learn freediving. Kate Winslet, playing Ronal the Metkayina spiritual leader, held her breath for 7 minutes and 14 seconds during an underwater scene, breaking Tom Cruise's previous record for an underwater filming sequence. Sigourney Weaver, playing the teenage Kiri at age 72 through performance capture, trained to hold her breath for six and a half minutes.

The film's most significant casting decision is one that takes careful explanation: Sigourney Weaver, who played Dr. Grace Augustine in the first Avatar and died in that film, returns in The Way of Water as an entirely different character. Kiri is a 14-year-old Na'vi teenager, the adopted daughter of Jake and Neytiri, who was born from Grace Augustine's unused avatar body through a process that is never fully explained — which is deliberately part of her mystery. Weaver, then in her early 70s, played the character through performance capture, preparing by sitting in on acting classes at New York's LaGuardia High School to study how teenagers moved, spoke, and held themselves. Cameron said during production that she looked genuinely younger and lighter during the capture period — she rarely stepped out of character. Kiri's unexplained connection to Pandora's neural network is the sequel's most significant unresolved mystery, and it manifests in the climax when she is able to summon and command sea life. The five Sully children are each played by specific actors and serve distinct narrative functions. Neteyam, the eldest and most responsible, is played by Jamie Flatters. Lo'ak, the impulsive second son who forms the film's central coming-of-age arc, is played by Britain Dalton. Tuk, the youngest, is played by Trinity Jo-Li Bliss. Spider — born on Pandora to a human mother and raised with the Sullys after being left behind when the RDA withdrew — is played by Jack Champion. Tsireya, the Metkayina girl who becomes Lo'ak's closest connection to reef life, is played by Bailey Bass, who is Kate Winslet's daughter in the film. Tonowari, the Metkayina chief, is played by Cliff Curtis. The screenplay was written by Cameron with Rick Jaffa and Amanda Silver, who had previously written Rise of the Planet of the Apes, from a story developed with Josh Friedman and Shane Salerno — a writing team assembled partly because Cameron's solo screenplay for the first Avatar had been criticized for simplistic dialogue.

The Metkayina are culturally and physiologically distinct from the Omaticaya forest clan Jake came from. Their bodies are broader across the chest and have flat, fin-like tails rather than the rope-like tails of forest Na'vi — adaptations for swimming at depth. Their spiritual connection to Pandora runs through the ocean rather than through trees, and their most sacred relationships are with the Tulkun: enormous, whale-like beings of extraordinary intelligence that are bonded to Metkayina families across generations. The Tulkun are also the reason the RDA has returned to Pandora's oceans. Human scientists have discovered that a substance called amrita, extracted from Tulkun brain fluid, is capable of halting human aging entirely. A single Tulkun yields enough amrita to make a human immortal, which gives the RDA's commercial operation a motive that goes far beyond unobtanium. The whaling operation is commanded by Captain Mick Scoresby, played by Brendan Cowell, who hunts Tulkun using tracker darts and rapid-extraction vessels. Lo'ak's arc is built around his bond with Payakan, a Tulkun who has been exiled from his own community because he fought back against human hunters — killing them in the process, which violates the Tulkun's absolute pacifist code. Lo'ak recognizes in Payakan a version of his own sense of not belonging, and the friendship they develop becomes the emotional anchor of his journey. Miles Quaritch, played by Stephen Lang, returns as a recombinant — a Na'vi avatar body loaded with the memories and personality of the original human colonel, who died at the end of the first film. He is sent to hunt Jake Sully specifically, and the presence of Spider — his biological son, raised by the Sullys — creates the film's most complicated emotional dynamic. Quaritch learns Spanish from Spider and uses their growing bond as a tool, while Spider's loyalty is genuinely divided.

The film's final act takes place across and beneath an RDA sea vessel during a battle triggered when Quaritch's forces capture Lo'ak, Tuk, and Tsireya aboard a Tulkun hunting ship. Neteyam is fatally shot during the rescue — dying in Jake's arms in the film's most devastating emotional scene. His death reshapes the ending completely: Jake had spent the entire film considering whether staying with the Metkayina was the right choice, and losing Neteyam while fighting a war he brought to their shores forces him to confront what he has cost both his own family and his hosts. Kiri's connection to Pandora saves Neytiri and Tuk when she calls sea life to break open the sinking ship. Spider rescues Quaritch from drowning at the climax — an act of instinct toward his biological father — but then returns to the Sullys rather than leaving with him, explicitly choosing the family that raised him over the man who created him. Tonowari formally adopts the Sully family into the Metkayina at the film's close, giving them a permanent home among the reef people. The film ends in an underwater moment of stillness — the surviving family together beneath the surface, Pandora's ocean around them, grief and belonging held simultaneously. Cameron has said the film was built around one line of dialogue: 'The sea gives and the sea takes,' spoken by Tonowari. That philosophy is the engine of everything in the film's second half. Three further Avatar sequels are in active development, with the next installment planned for December 2025.