The Desolation of Smaug, the subtitle of the second installment in Peter Jackson’s trilogy of films based on J.R.R. Tolkien’s The Hobbit, is a pretty apt indication that the movie has darker, more ominous intentions than its predecessor, 2012’s silly, exposition-weighted An Unexpected Journey. Still, a better title might’ve been Running With Dwarves.

In order to stretch this children’s story into three movies, Jackson has injected them with a small library’s worth of back story and enough atmosphere to crush an oliphant. But it turns out his most important innovation—-one that did little to help An Unexpected Journey but gives this film a surprising, gratifying fleetness despite its 169-minute run time—-was turning a book about a quest into three movies about a chase.

When the film begins—-well, following a tension-ratcheting prelude set in the Hogsmeadesque town of Bree, where everybody scowls—-our band of 12 dwarves, one hobbit, and a gigantic-by-comparison Ian McKellen is still on the run from a pack of orcs. The protagonists seem to have lost the ground they gained in the last movie, which ended in an instance of deus ex machina via giant eagle. Now they must avoid the hunting party led by the one-armed Azog the Defiler—-he’s basically the Darth Maul of orcs—-and a massive bear-like creature that titular hobbit Bilbo (Martin Freeman) has spied lurking in the mountains. Soon Bilbo and the dwarves, on their way to the Lonely Mountain to kill a dragon and reclaim the stolen treasure of a fallen dwarf kingdom, will find a new ally and passage into the murky woods of Mirkwood Forest, while Gandalf (McKellen), their wizard companion, will break off from the pack for a task of even spookier import. There’s a trouble-making sorcerer whose intentions Gandalf must decode so he can understand what we already know from Jackson’s Lord of the Rings films, set about 60 years after The Hobbit: Sauron, that trilogy’s big, bad, floating stink-eye, should not be fucked with lightly.

All of which is, well—-woof. Good thing, then, that Jackson is mostly concerned with momentum. He smartly slows it in cobweb-strewn Mirkwood, a forest so thick with menace that the company of dwarves trips balls on its evil dust as a chorus of whooshes and threatening whispers builds to a sickening crescendo. When Bilbo climbs above the canopy to see how far they’ve walked, it feels as though he’s stepped from the setting of Antichrist into an outtake from “Bound 2.” (There are blue butterflies and a Lisa Frank sheen, as far as the eye can see.) Soon he’s back in the forest, using his invisibility ring and stabbing a massive spider in the face. Just as the film has darkened, so has the once-naive Bilbo, an unlikely and always underestimated hero who, like his nephew Frodo from Lord of the Rings, animates what might otherwise be a Manichean downer.

The pace—-and surely some fanboys’ hearts—-picks up with the arrival of Legolas (Orlando Bloom), the eternal bow-wielding elf from Lord of the Rings, who, ricocheting off an impossible number of trees, drops in on the spider fight like he’s Errol Flynn on whip-its. He transports the dwarves as prisoners to the realm of the woodland elves. Eventually we’ll explore more settings—-a gloomy town of humans that appears to have been transplanted from prerevolutionary France, and then the dragon-housing Mount MacGuffin—-but first the chase must resume with a barrel-aided Escape from Splash Mountain. Orcs will chase dwarves, elves will chase orcs, severed orc heads will fly at your face because no opportunity to remind you that this thing is in 3D can be missed. It’s never clear why this sequence wasn’t filmed on SplashCam.

But Jackson’s touch—-cartoonish when it needs to be, the correct degree of fraught the rest of the time—-is right, and the film only begins to creak when Bilbo finally encounters the silky-speaking dragon of the film’s title. Smaug is voiced, deliciously, by Benedict Cumberbatch, but you don’t introduce a dragon in the third act if it’s not going to go off approximately three minutes later. Unfortunately, this fire-breathing reptile likes to play with his food.

But hey, we’ve got a whole third movie to see what Smaug can really do—-and if your heart doesn’t race from The Desolation of Smaug‘s whoa-shit ending, it’s colder than the Witch-king of Angmar‘s tit. Much of what Jackson has added to this simple tale in the pursuit of making an extra billion dollars shouldn’t feel necessary. Nevertheless, following a dreary first installment, he’s finally taken us on an unexpected journey, indeed.