Born in the 3-D land rush, “How to Train Your Dragon” has never quite shrugged off the bland corporate sheen attached to it from the start. But almost a decade since taking flight in 2010, these movies have made up for their lack of fire with enough sincerity and genuine sense of wonder to sustain a mild but moving trilogy.

“How to Train Your Dragon: The Hidden World” brings the franchise to a close with an affectionate chapter that continues the adventures of the Viking boy-turned-chief Hiccup (Jay Baruchel) and his faithful dragon Toothless, a sleek, black kind of dragon called a Night Fury (not to be confused with an evening-time presidential tweet storm).

In “The Hidden World,” the dragon utopia that Hiccup has built on the Island of Berk, where Vikings once feared and fought dragons, comes under threat from a dastardly dragon hunter named Grimmel the Grisly (F. Murray Abraham) whose toothy grin resembles a moonlighting vampire with violently retrograde policies on dragon coexistence.

With Berk under attack, Hiccup rallies the Vikings to uproot and flee to a mythical, undiscovered realm called the Hidden World where dragons could live safely away from humankind. It feels like an overreaction. Fearsome as Grimmel is, he’s a single and kind of goofy villain, and, plus, real estate values in hidden worlds are notoriously unpredictable.

Written and directed by series veteran Dean DeBlois, “The Hidden World” may not overwhelm in its necessity; it’s a tale that lacks the stakes of the previous installment, which dealt significantly with Hiccup’s parents — the discovery of one (Cate Blanchett) and the death of another (Gerard Butler). But the $1 billion in box office taken in by the first two movies, combined, was enough to push the franchise forward and put “How to Train Your Dragon” back into action five years later (and following the sale of DreamWorks to Universal).

There are two compelling parts of “The Hidden World” that validate it. The first is the courting scene between Toothless and another white (and presumably female) Night Fury who turns up just as Grimmel does. They swoop and swoon through the sky, gliding in the glow of the Northern Lights like a dragon version of “La La Land.”

The second is the film’s terrific coda, which leaps years forward and adds a wider, wistful and more grown-up dimension to what has always been, at its heart, a boy-and-his-dog story, just with wings.

“How To Train You Dragon” has done a lot of things right along the way. It brought in cinematographer extraordinaire Roger Deakins to add to the rich Nordic atmospherics. (Deakins remains credited as a visual consultant in “The Hidden World.”) And the series deserves credit, too, for building a story — adapted from Cressida Cowell’s books — around two unimpeded protagonists (Hiccup and Toothless) with prosthetic appendages.

Without much to draw on from the surrounding characters (voices include America Ferrera, Jonah Hill and T.J. Miller), “How To Train Your Dragon” has always been predicated on that central twosome and the laudable lesson that animals, even fire-breathing ones, aren’t our enemies unless we make them so.

“HOW TO TRAIN YOUR DRAGON: THE HIDDEN WORLD”

** 1/2

(PG, 1:44)