

The writers’ key structural innovation here is to incorporate material from “The Quest of Erebor,” one of Tolkien’s supplemental “Unfinished Tales,” starting with a prologue that flashes back to a secret early meeting between the noble dwarf Thorin Oakenshield (Richard Armitage) and the gray wizard Gandalf ( Ian McKellen).

Still, “The Desolation of Smaug” reps a major improvement on its predecessor simply by virtue of picking up at a more eventful place in the narrative, and as scripted by the returning team of Jackson, Fran Walsh, Philippa Boyens and Guillermo del Toro (who was slated to direct at one point during “The Hobbit’s” troubled production history), the film immediately evinces a livelier pace and a heightened sense of urgency. Good and evil are still very much at stake, sometimes grippingly so, but even the staunchest Tolkien loyalists may feel they’re on an overly protracted journey to an inevitably less exciting destination.

Whereas the “Rings” movies felt as pure, vital and heroic as the Fellowship’s mission itself, this three-part prequel can’t help but seem like a more mercenary endeavor as it drags out Tolkien’s slender tale of a band of dwarfs seeking to reclaim a lost fortune. Although Jackson’s “Hobbit” pics have maintained an impressive visual continuity with his incomparable “Lord of the Rings” trilogy (technological upgrades like 3D, Imax and high frame rates notwithstanding), the fundamental difference between these two series may be as simple, yet instructive, as the contrasting stories they tell.
