Thor 2: The Distruction Of The Bifrost Bridge Is Key

"Thor: The Dark World" executive producer Craig Kyle told Screen Rant that the ending of the first "Thor" film and how events in "The Avengers" help to set up the certain plot points that are part of sequel.

The destruction of the Bifrost Bridge (rainbow bridge), which allowed for easy travel between the nine realms, is a major part of the Thor 2 story:

"The Bifrost was destroyed at the end of the first Thor. Odin had to break a lot of rules and laws, and take a lot of himself to send Thor to Earth in The Avengers. And during that time when they couldn’t jump from Asgard to the other worlds chaos reigned. And so we come into a time of real strife in the nine realms. You’ve got Marauders who are moving from world to world that are pillaging and attacking helpless planets, because they know the cops can’t come. And we just catch into a story in a way finding out where the hell is everybody, you know?"

 

The sequel is directed by Alan Taylor and on a larger scale than the first film with double the amount of Asgardian characters and the inclusion of Thor (Chris Hemsworth) battling more mythical Norse creatures.

Natalie Portman is back playing Jane. Tom Hiddleston is once again bad boy Loki Kat Dennings will reprise her role as Darcy Lewis, the spunky sidekick to Portman's from the first film and Idris Elba will be reprising the role of Heimdal. Jamie Alexander plays Sif, ‘Chuck’s’ Zachary Levi is lined up to replace Josh Dallas who will not reprise his role as Warriors Three member Frandral Hopkins will be back playing Thor's pops. Christopher Eccleston will play the villain--the character of Malekith The Accursed, is the ruler of the Dark Elves of Svartalfheim and has magical abilities including teleportation, energy projection, flight, and shape changing ability. He also has a weakness to iron which cancels out his powers. Eccleston takes over from Mads Mikkelsen who was originally slated to play the part but had to pass due to scheduling issues with the Hannibal TV show.The great Alice Krige ("Star Trek: First Contact," "Silent Hill") will play the Dark Elf queen Alflyse. Richard Brake will play a captain in an elite squad of warriors known as the Einherjar. Clive Russell ("Sherlock Holmes") will play Tyr, Asgard’s god of war and the older brother of Thor.

The film's villain Malekith, holds a personal grudge against Odin. With Odin broke some major rules to send Thor to Earth, those actions will have big consequences for all of Asgard.

"Saving Private Ryan" scribe Robert Rodat is said to have performed a re-write of the sequel. First Thor co-writer Don Payne had written the first draft. It was recently revealed that Joss was brought in to help solve a few issues with the screenplay.

The sequel hits theaters on November 8th 2013