Universal / DreamWorks Animation

The How to Train Your Dragon series occupies a particularly vital spot in the world of animated fables. Other hit films such as Kung Fu Panda and Spider-Man: Into the Spider-Verse are stirring tales of heroism and maturity; recent Pixar classics such as Coco and Inside Out examined the bonds of the family unit through the eyes of kids on the verge of growing up. The Dragon trilogy, directed by Dean DeBlois, hits all those marks, but it’s also a highly adorable tale of responsible pet ownership, and for that reason alone it should probably endure in the annals of pop culture.

The first How to Train Your Dragon was released in 2010 and quickly became one of the most critically acclaimed offerings from DreamWorks Animation, the studio that has pumped out franchise after franchise over the decades (including Shrek, Kung Fu Panda, Madagascar, and a forthcoming The Boss Baby sequel). Dragon stuck out with its impressive visuals and grand fantasy storytelling, and in 2014 the second film added a surprisingly melancholic tone. Now, five years later, comes the final chapter, subtitled The Hidden World, in which the touchy-feely Viking Hiccup (Jay Baruchel) and his sleek, jet-black dragon pal, Toothless, have one last life lesson to impart about the importance of letting things go as you grow up (and, yes, about the unbreakable bonds that exist between pet and owner).

Hiccup’s island community, a bustling oasis called Berk, has become a dragon metropolis in The Hidden World. The fire-breathing lizards were frightening enemies in the first film, but the friendship between Hiccup and Toothless, which is animated like an excitable puppy, changed all of that. By the third entry, every Viking in town is riding a dragon steed, and Hiccup—having transformed from stammering, awkward teenager to inventive, dynamic warrior—has become the village chief. He’s even boasting a little stubble this time around and taking on a tinge of Game of Thrones–scale epic action.

But these developments are more derivative than thrilling. As much as human-dragon relations have advanced, the individual characters indicate that the series is out of ideas. Hiccup’s main preoccupation in The Hidden World is the emergence of Grimmel (F. Murray Abraham), a slab-faced dragon hunter who has the not too compelling motivation of wanting to kill the creatures and mount them as trophies. Abraham does his mellifluous best to give Grimmel some flair, but he’s mostly an obstacle to be swept aside by the more compassionate Vikings. The characterization of the rest of the ensemble—whether Hiccup’s comical pals (voiced by actors including Jonah Hill, Christopher Mintz-Plasse, and Kristen Wiig) or his stoic warrior mother, Valka (Cate Blanchett)—has always felt a little stock. As a result, the narrative thrust of The Hidden World sputters any time humans are involved. Much of the plot exists only to stall the characters until the film winds its way to a touching conclusion.

Toothless, meanwhile, encounters a female dragon of the same sleek species as himself, though her scales are all white rather than black, making the pair look like two different iPhone editions together. In one stupendous scene, they flirt as only dragons can, bleating and barking at each other as they zip around the island (assisted by a soaring score from John Powell, the most valuable player of all three movies). Their newfound love means it’s time for Toothless to grow up just as his human pals have, journeying to a secret paradise for dragons called “the hidden world.” Where the first two How to Train Your Dragon films were about fostering understanding between humans and dragons, the third is about the value of letting these creatures pass into myth.

Eye-catching splendor has always been the biggest draw here. The legendary cinematographer Roger Deakins is credited as a visual consultant on the series, helping to devise the films’ dynamic flying sequences, and The Hidden World boasts wonderfully designed environments that sparkle with color. The dragons themselves, which come in all shapes, sizes, and hues, are a delight to behold. The bond between Hiccup and Toothless has been well developed enough over these three films that the heartfelt last 20 minutes work. So much of The Hidden World is stuffed with filler material. But in certain wordless moments, this grand final entry really sings.

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.