As war rages across England, Lucy (Georgie Henley) and Edmund (Skandar Keynes) have moved in with their uncle, while enduring the pestering presence of their snotty cousin, Eustice (Will Poulter). When the magical land of Narnia requires their return, the trio is pulled back into their lost kingdom, arriving on the Dawn Treader, a massive ship belonging to Prince Caspian (Ben Barnes). Learning of an exceptional evil that necessitates the collection of seven royal swords to eradicate, the team sets sail for the edge of the world, bringing along mouse soldier Reepicheep (voices by Simon Pegg) for protection. On this journey, the group is haunted by their fears and envy, exploited by the powers of a dark island while Eustice, struggling to learn the rules of Narnia, is accidentally transformed into a dragon.

The world that C.S. Lewis laid out for “The Chronicles of Narnia” has been treated with white-gloved respect throughout these three pictures, but it’s a museum appreciation, lacking distinctive cinematic firepower to launch it skyward. “Dawn Treader” makes a significant effort to up the action quotient of the material, setting sail on a sequel that’s mindful of forward momentum and swashbuckling efforts, compelling director Michael Apted to crudely cram in character progression along the way. For the first act, there’s electricity here that elevates the franchise, finding a new adventurous purpose beyond the observance of Narnia wonderment. For 40 minutes, the picture parries, leaps, and sprints around, pushing the characters to work up a healthy sweat as the quest is established, arcs commence, and Aslan (the droning Jesus-lion, voiced by Liam Neeson) is blessedly nowhere to be found.

Once the gang busts up a slave colony and kicks off the hunt for the swords, the excitement of the film deflates rapidly, with the script quickly weighed down by the needs of adaptation, creating little moments for all voyagers involved to keep them busy. It’s a question of maturation and vanity for Lucy, an internal struggle with heroism for Edmund, leadership blues for Prince Caspian, and general pissing and moaning from a disorientated Eustice. Pausing the special effects kills the established oomph, bestowing tedious exposition to actors who aren’t skilled enough to make their transformations interesting, led around by an overwhelmed Apted, who shows a shocking disregard for metered reaction. If it isn’t a slack-jawed, bug-eyed close-up of wonder, it’s not in this movie. A hardcore demonstration of obnoxious behavior emerges from Poulter, who wildly overplays his role as the runt of the Narnia litter. The young actor is pure agony to watch, shrilly stomping around the frame without a leash to make points of discontent that demand a more refined touch of humiliation. Poulter’s scenes are simply unbearable, rendering Eustice’s journey from brat to fire-breather something to dread, not enjoy.

Cameos from previous Narnia residents help the continuity out, and Pegg’s interpretation of the pirate mouse is expectedly rich with wit and friendly tones of animated encouragement. While the star power is welcome, it can’t fight spirituality, as the subtleties of the Christian themes that flow throughout the series are decidedly more pronounced for the third round. Talk of belief, faith, sin, and a few appearances from God himself, Aslan, helps to broadly underline the real quest of the characters: to reach Heaven. The spiritual sentiment isn’t the offense, only the primitive delivery, destroying the mystery of Narnia and its all-holy cat.

Cursed with a bothersome 3D overlay (placing annoying sunglasses on ace cinematographic work from Dante Spinotti) and ho-hum monsters (an attacking sea serpent looks pulled directly from “Predator”), “Dawn Treader” has many obstacles to hurdle before it finds an ending. Mercifully, there’s a tone of finality here, at least for most of the characters. Barring a box office disaster, the franchise will live on, albeit in the clammy hands of flared-nostril wuss Eustace. Aslan, take me with you!

C