At the start of “The Hobbit: The Desolation of Smaug,”^[1] the second part of Peter Jackson^[2]’s extended-play adaptation of J. R. R. Tolkien^[3]’s children’s book, Bilbo Baggins has a sword called Sting and One Ring to Rule Them All — eventually. We have a ways to go. As everyone on Earth and in Middle-earth surely knows, Mr. Jackson, having turned Tolkien’s trilogy “The Lord of the Rings”^[4] into three hit films, has given its prequel a blockbuster do-over in three separate 3-D movies. The first, “The Hobbit: An Unexpected Journey^[5],” a soporific 170 minutes released in 2012, lived up to its subtitle principally by moving at a snail’s pace. At 161 minutes the new one by contrast feels like a sprint. (The third, “The Hobbit: There and Back Again,”^[6] is set for world domination^[7] in December 2014.)

Once again, Martin Freeman^[8] plays Bilbo, the homebody hobbit who has been enlisted by a band of boisterous dwarfs to help reclaim their lost kingdom and vast treasure from a gold-stoned dragon, Smaug, voiced with hypnotic, sepulchral menace by Benedict Cumberbatch. (The casting for Bilbo and Smaug constitutes a reunion of sorts because Mr. Cumberbatch plays, dazzlingly, Holmes on the BBC television show “Sherlock,”^[9] in which Mr. Freeman holds the center as Watson.) When the movie opens, Bilbo, the dwarfs and the wizard Gandalf the Grey (Ian McKellen), are closing in on Smaug, who lords over the lost dwarf kingdom in Lonely Mountain. Having endured loads of trouble in the first movie — lions, tigers and bears, or rather trolls, orcs and stone giants — the travelers are in for more.

And how: Mr. Jackson, like many contemporary directors given enormous resources to play with, likes to pile it on. With “The Desolation of Smaug,” he has taken roughly five chapters from the middle of Tolkien’s book and turned them into a relentless adventure tale, teaming with rowdy action, slavering enemies and Elven gymnastics. (It was written by Mr. Jackson, Fran Walsh, Philippa Boyens and Guillermo del Toro.) There are giant spiders, wolves called Wargs and one pleasingly familiar face, that of Legolas, the Elven heartthrob played by Orlando Bloom^[10], who swoops into the mix and, like Luke Evans, as a mystery man named Bard, gives the movie some oomph. There’s also the skin-changer, Beorn (Mikael Persbrandt), who divertingly transforms from man to beast and gives Bilbo and company shelter.

There’s more, much more, including a layover in the Elven kingdom, where the imperious Elvenking, Thranduil (Lee Pace), gads about in flowing robes and locks like a petulant supermodel. He’s a bore and a drag — he imprisons the dwarfs and whines constantly — but Legolas, with his darting moves, is a delight, as is another Elven warrior, Tauriel (Evangeline Lilly). A filmmaker invention, Tauriel was created to femme up the nearly all-male world of the “Hobbit” and is one of the better realized and welcome liberties taken with a book that Tolkien, who fought and studied among men, wrote between the two world wars. So it’s irritating that she’s saddled with a romance, a pandering turn that suggests Mr. Jackson, unlike his female fans, can’t even imagine a woman without a man.

It isn’t that the romance is badly handled: it actually creates a bit of a breather and shines some light into a galumphing, often grim movie. Rather, it’s the conventionality, the lack of surprise and poverty of imagination that’s gone into the creation of the only woman in the movie with an active, substantive role and which speaks to Mr. Jackson’s weaknesses as a director. Because when he is good — as in the first “Lord of the Rings” and in scenes here and there in its sequels and in this movie — he is very, very good. But when he is bad he’s a crushingly straight, unoriginal director who seems largely interested in topping himself with bigger, louder, more frenetic action and who all too often hits his beats as predictably as someone doing hack work for Jerry Bruckheimer.

The good Mr. Jackson dukes it out with the bad throughout “The Desolation of Smaug.” There are, once again, too many busy, uninterestingly staged battles that lean heavily on obvious, sometimes distracting digital sorcery. But there are also pacific, brooding interludes in which the actors — notably Mr. Freeman, an intensely appealing screen presence — remind you that there’s more to Middle-earth than clamor and struggle. “They were come to the Desolation of the Dragon,” Tolkien writes partway through “The Hobbit,” in a line that conveys the stateliness of purpose of Bilbo’s journey and its foreboding, “and they were come at the waning of the year.” For a few pleasurable moments, Mr. Jackson pauses at the edge of this poetic cliffhanger — and then barrels right over.

“The Hobbit: The Desolation of Smaug” is rated PG-13 (Parents strongly cautioned). Middle-earth violence.

References

1. ^{^} “The Hobbit: The Desolation of Smaug,” (movies.nytimes.com)
2. ^{^} Peter Jackson (movies.nytimes.com)
3. ^{^} More articles about J. R. R. Tolkien. (topics.nytimes.com)
4. ^{^} “The Lord of the Rings” (movies.nytimes.com)
5. ^{^} Times review (www.nytimes.com)
6. ^{^} “The Hobbit: There and Back Again,” (movies.nytimes.com)
7. ^{^} more here"HYPERLINK "http://www.hollywoodreporter.com/news/third-hobbit-film-sets-release-367258" o "more here (www.hollywoodreporter.com)
8. ^{^} Martin Freeman (movies.nytimes.com)
9. ^{^} Times review (www.nytimes.com)
10. ^{^} Orlando Bloom (movies.nytimes.com)