Avatar: The Way of Water is finally out after a 13-year-long wait. Not only does the Avatar sequel expand the world of Pandora, it also brings new elements into the franchise that will surely be explored at a later date. There's been talk of as many as 7 Avatar films when all is said and done, though James Cameron has said the sequels will be cancelled if Avatar: The Way of Water fails.
Right now, that seems like an unlikely prospect. Of course, nothing is set in stone, but Avatar: The Way of Water has brought in more than $400 million in its first three days in theaters. When its theatrical run ends, Avatar: The Way of Water will reportedly need to be the fourth or fifth highest grossing film of all time to break even. That's a tall order, but Cameron has a lot of faith in the franchise, and he's planning ahead. There are many elements in The Way of Water that lay the groundwork for future sequels set on the world of Pandora.
Colonel Quaritch
Played by Stephen Lang, Quaritch makes his return in Avatar: The Way of Water. This isn't necessarily the Quaritch from the first film, however. At the end of the original movie, Quaritch was killed by Neytiri (Zoe Saldaña) as she protected Jake (Sam Worthington) from his wrath. This version of Quaritch is actually a Recombinant — a sort of Avatar clone, a hybrid of Na'vi and human DNA that contains the memories of Quaritch.
Part of Quaritch's evolution in Avatar: The Way of Water involves him coming to terms with his identity. He acknowledges he's not quite the original Quaritch, and that he isn't even the same species, but by the end of the film, his relationship with Spider (Jack Champion) is what ties him to his old life. Spider is actually Quaritch's son, conceived with another soldier before the climactic battle in Avatar.
Spider turns out to not want anything to do with Quaritch and his attempts to colonize Pandora. He firmly identifies with the Na'vi. On the other hand, Spider does save Quaritch's life, and Quaritch tries to get him to fly away with him, which Spider declines. But Quaritch is still out there. He may or may not end up back at Bridgehead City, or he could end up going rogue, seeking revenge on the Sully family. He's also more connected with Pandora, being able to tame some of the wild beasts there. When Quaritch comes back for another Avatar sequel, he'll be a very different character from who he started out as.
Human Colonization
The human colonization efforts are not stopped by the end of Avatar: The Way of Water. Though humans were kicked offworld at the end of the last movie, they didn't stay gone. About a year prior to the main events in the second film, humans returned to Pandora and devastated a large plot of land there. They've since established Bridgehead City in that area, and though it's currently only housing soldiers, it's clear that they won't be the human inhabitants of the area.
Early on in the film, it's established that the Earth is dying, and will no longer be able to support humanity. For that reason, humans are planning to colonize Pandora after they've "pacified" the Na'vi. Jake ultimately chooses to flee far away from the colonization efforts; he reasons that it's his presence that puts the Na'vi in the most danger. Without him there, the army won't be as relentless when attacking the Omaticaya. Unfortunately, this decision means that there's no one in a position to stop the colonization of the area, and humanity will probably have a pretty solid foundation to expand their colonization efforts by Avatar 3.
The lack of breathable atmosphere for humans on Pandora could also become an issue in the future, if terraforming is something humanity has up its sleeve. Though the Na'vi can breathe in an Earth-like atmosphere, it's only for a few hours; they can't survive in it indefinitely.
Amrita
Avatar: The Way of Water shows off even more of Pandora than its predecessor did. The film reveals that there's actually another sentient species on Pandora: the tulkun. A gentle, whale-like race, they're actually quite capable of communicating with Na'vi. Humanity has begun hunting them, but it's not for food. Tulkun have some special properties, and their brains contain Amrita.
Amrita is a chemical that only appears in a brief sequence in Avatar: The Way of Water. It isn't a big focus in the film, but its implications are massive. Not only is Amrita incredibly valuable, it can stop human aging in its track. It appears to be the key to eternal youth, and just one vial costs $80 million. When the colonization efforts begin to bring in civilians in their millions, or even billions, humans will surely begin trying to take down as many tulkun as they can.
The Sully Family's New Tribe
The Sully family gets a lot of character development in this film — it's actually the reason for Avatar: The Way of Water's extended runtime. When they leave the Omaticaya behind, Jake takes his family to join up with the Na'vi Sea Peoples, and they become Metkayina. They're officially welcomed into the tribe by the end of the film, but the army now knows where the Sullys are hiding. The Metkayina are committed to keeping their own safe, so they probably won't be forced away, but who's to say the Sullys won't have to leave again to keep their new tribe safe?
One of the Sully sons in the film, Lo'ak (Britain Dalton), also forms a romantic connection with Tsireya (Bailey Bass), the Metkayina chief's daughter. Avatar has been described as a multigenerational tale, and the development of this relationship could shape a lot of the franchise's future. Not only would any children between them be a Forest Na'vi/Sea Na'vi hybrid (and the two groups appear to have some animosity with one another), they'd also be part human, and the Na'vi refer to part human hybrids as "demons."
A Greater Connection to Eywa
The Sully family's adopted daughter, Kiri, has a surprising connection with Dr. Grace Augustine (Sigourney Weaver) from the first film. Kiri is actually Dr. Augustine's biological daughter, born of her Avatar body after the events in Avatar. Her father is unknown, but she has a strong connection with Eywa. She even appears to control Pandora's environment to a great degree.
Her connection with Eywa isn't explored or explained in depth during Avatar: The Way of Water, but it's clear that the franchise intends to explore that more in the future. Additionally, Cameron revealed he cancelled an Avatar sequel because it didn't have the right amount of spirituality. Eywa's presence is probably going to be a big deal moving forward, as the worship of the Na'vi's deity is the main source of spirituality in both films.
Cameron has already revealed that Avatar 4 is further along than fans expect, and producer Jon Landau has said that the opening act for Avatar 4 has already been filmed. The sequels are supposed to come out much faster than Avatar: The Way of Water, and the schedule appears to support that. Avatar 3 is scheduled for December 20, 2024, and Avatar 4 is set for December 18, 2026.