The first “Avatar” took the world by storm in 2009, because it was something moviegoers hadn’t seen before – a blockbuster, with a message, whose world building was almost entirely computer-generated.

James Cameron brings the same approach to a new biome of Pandora in “Avatar: The Way of Water,” while doubling down on that most elusive of elements in sci-fi films: heart.

Thirteen years ago, Avatar’s Endor-like, Saturnian moon Pandora enchanted audiences. Here, the aquatic home of the Metkayina Na’vi is just as immersive as the first film, if not more.

Russell Carpenter’s sweeping cinematography and Simon Franglen’s thrilling score help audiences feel like they are navigating the Pandoran waters themselves. Whale-like Tulkun Payakan is more of a character than an animal, and actually has a better arc than some of the main protagonists in the film.

The relationship between the human Jake Sully, played by Sam Worthington, and the Na’vi Neytiri, played by Zoe Saldaña, is at the center of the Avatar films and is what separates it from the rest of the crowded sci-fi genre. “The Way of Water” brings several new characters into the mix, but the emotional core of the story is Sully’s and Neytiri’s family: Neteyam, Lo’ak, Tuktirey “Tuk,” and adopted kids Kiri and Spider.

Youngest child Tuk is left behind as most of the plot follows Neteyam, Lo’ak, and Kiri, with Spider being in the B-story. The problem with this is that Neteyam and Lo’ak aren’t referred to by their given names enough, with the result being that the two brothers are solely distinguished by their age. It doesn’t help that they also look similar to one another.

Kiri, played by returning cast member Sigourney Weaver, has one of the more interesting arcs of the film, as she goes from an outcast as a half-breed in the Metkayina tribe to saving the day with her Eywa-derived nature powers.

An outsider among the Sully clan, Spider Socorro’s parentage is constantly hanging over him, as he spends much of the film in the throes of a clone of his father, the deceased Colonel Miles Quaritch. This is one of the rare points where “The Way of Water” stumbles.

Socorro spends the entire film not wanting to be associated with Quaritch, who is as evil as ever, but saves him in the end in a classic “We have to be better than the bad guys” moment. This would have been better if we spent more time with Socorro and his motivations.

Neytiri’s arc also comes up short, as it is established that she has a bloodlust after Neteyam’s death, but we never quite believe that she is willing to kill Socorro.

The everyman protagonist of “Avatar,” Sully’s arc is predictable, but executed well. Metkayina chief Tonowari (Cliff Curtis) and his wife Ronal (Kate Winslet) are just sort of there, while their daughter Tsireya (Bailey Bass) doesn’t have much of a personality beyond being nice.

While the writing could be improved in certain aspects, “Avatar: The Way of Water” builds on the success of the first film: building an immersive world, sending an eco-friendly message without being preachy, and making characters that we can root for even through motion capture. I can definitely see it continuing for three more films.