Review: Thor 2: The Dark World, by Rich Cline. 

4/5 - "Excellent"

Marvel can't help itself: these movies have to get bigger and crazier. And this one leaves us wondering where they can possibly go next, as it spirals into a madly funny-scary thriller that threatens the existence of the whole universe. But it also feels like a story children would make up as they go along. Still, the sparky characters and wildly cataclysmic approach are hugely entertaining.

Natalie Portman Thor 2Natalie Portman as Jane Foster in 'Thor 2: The Dark World'

The action picks up right after the Battle of New York (see 2012's The Avengers), and scientist Jane (Portman) is miffed that Thor (Hemsworth) didn't call when he was back on Earth.

She has just started dating a nebbish Londoner (O'Dowd) when her assistant Darcy (Dennings) stumbles into a spatial anomaly that draws Jane right into the middle of a 5,000-year-old struggle between Thor's home-realm Asgard and the dark elf Malekith (Eccleston), who wants to use a swirling goo called the Aether to plunge all of existence into blackness just as the universe aligns itself. As this convergence approaches, Thor defies his father Odin (Hopkins) and turns to his disgraced, malicious brother Loki (Hiddleston) for help.

The film is overcrowded with small but pivotal characters, including stern but helpful gatekeeper Heimdall (Elba), mad-doctor Erik (Skarsgard) and Odin's wise wife Frigga (Russo). All of them help distract us from the movie's wildly shifting tone as it darts from sardonic comedy to Lord of the Rings-style battles to silly romance to dark emotion.

But the best thing is the tense, unpredictable relationship between Thor and Loki, an enjoyable mixture of sibling rivalry and brotherly love that's well-played by Hemsworth and especially Hiddleston. None of the other characters really has a chance to develop around them. But at least the actors have fun with their roles, including a number of hilarious cameos along the way (there are also two post-credit stings).

Yes, this is a massive-scale adventure, and it helps that the portentous storyline is undermined continually by jagged sarcasm. We don't even mind that the script is packed with lazy plot devices, including a continual series of holographic double-bluffs and spatial gateway nonsense.

All of this combines to create an exhilarating climactic action sequence in London that ramps up the suspense and keeps us smiling even though it's impossible to make any real sense of it. And since the movie essentially maintains its focus on the relationships between the characters, it leaves us gasping for more.

Watch the 'Thor 2: The Dark World' trailer: