Us Rating: ***

In Twilight's first four movies, Bella (Kristen Stewart) was a mopey, passive, lower-lip biting wallflower. But by the franchise's final film, she has become a bloodythirsty, aggressive and downright glowy woman, complete with voluminous hair right out of a L'Oreal ad. She has blossomed.

The series has matured as well. While still plenty cheesy and packed with poor special effects, the film is at last in on the jokes, with intentional laughs and gloriously over-the-top moments, including one audience-thrilling twist that will surprise even faithful readers of the books.

The story picks up where Breaking Dawn - Part 1 left off, just after Bella gives birth to half-mortal daughter Renesmee (Mackenzie Foy) and hubby Edward (Robert Pattinson**) turns her into a bloodsucker to save her from death. Having gained super strength, Bella bolts through a forest, wins an arm-wrestling contest with muscled-up Emmett (Kellan Lutz**, whose vampire makeup, after all these movies, still looks terrible) and attacks a mountain lion for her first taste of blood. And the sex! "We don't get tired," she tells Edward after a session of vampire lovemaking. "I'm never gonna get enough of this."

Alas, the afterglow wears off and new issues arise. First, Bella and Edward don't know why Renesmee is aging at such a rapid rate. More urgently, the Volturi -- the ruling class of Italian vampires headed by the wicked, campy

Aro (Michael Sheen, having a ball) -- wrongly believe that Renesmee is a child vampire (a kid bitten by a bloodsucker) who will endanger the future of the undead worldwide.

While the Volturi plot to confront the Cullens, Bella and Edward prep for battle with their usual crew. This includes Bella's former suitor, the ab-tastic Jacob (Taylor Lautner**), who strips down to his underwear before turning into a werewolf in one of the film's most laughable, self-aware scenes. (Director Bill Condon could probably hear the teen girls screaming when he filmed it!) Jacob -- who "imprints" on Renesmee (meaning he'll be her guardian and partner for life, ick) -- actually has more to do this go-round than Edward, who mostly just stands around looking pretty until the climax.

For a franchise that's never been known for its action sequences, the hellazapoppin finale is downright fun. And in some ways, shocking. The showdown between the Cullens' vampire network and the Volturi deviates so wildly from Stephenie Meyer's book, fans will guffaw. And with so much jaw-dropping brutality, it's stunning the movie snuck by with only a PG-13 rating.

Still, even casual Twilight viewers won't be surprised about the eventual happily-ever-after. The frighteningly successful series, which has earned $1 billion in the U.S. alone, wraps up with a When-Bella-Met-Edward flashback that pushes all the right romantic buttons. The future of Stewart and Pattinson's off-screen relationship may be uncertain at this point. But the montage reminds viewers that for fans, Bella and Edward will always be movie magic.

This article originally appeared on Usmagazine.com: Review: Breaking Dawn Part 2 Has "So Much Jaw-Dropping Brutality"