The Star Trek Into Darkness trailers have emphasized massive destruction, including terrorist attacks and crashing starships. But how does all of this fit together? And why haven't we yet glimpsed the mysterious but vital character played by Peter Weller? A ton of footage was shown in Brazil, which gives away a lot of the movie's first act and some stuff that happens later.
Depending on which account you go by, the Brazilian audience saw around the first 28 minutes of the film, plus a few scenes from later on in the movie. Among other things:
Peter Weller is playing Admiral Marcus, the father of Carol Marcus, Kirk's love interest. Even though we were told Weller was playing a villain, there's no indication of that early in the film.
So if you saw the IMAX preview in December, you already saw some of the opening of the movie — but it's been changed around since then. Now it starts with the Enterprise on the volcano planet, with Spock lowering into the volcano and Kirk trying to decide whether to save his friend or follow the Prime Directive. Spock says the needs of the many outweigh the needs of the few, but Kirk chooses to save Spock anyway. Kirk claims the natives didn't even notice the disruption.
Then, after the credits, we go to the scene where Noel Clarke and Nazneen Contractor are in the hospital with a sick child — and John Harrison (Benedict Cumberbatch) offers to save their child, for a price. Soon enough, Harrison is giving the kid some medicine, and Noel Clarke is using his Starfleet ring as a bomb to cause a terror attack at a library in London. (Or in one version I read online, it's John Harrison who uses his Starfleet ring as a bomb.)
Meanwhile, the Enterprise crew returns to Earth, and Kirk hooks up with two hot alien cat women — but then Kirk gets summoned to meet Admiral Pike at Starfleet. Kirk hopes this means the Enterprise is about to be sent on its five-year mission at last... but instead it turns out that Spock told Starfleet about violating the Prime Directive, while Kirk lied on his report and tried to cover up the whole business. Pike is going to resume command of the Enterprise, while Kirk goes back to the Academy. But after Admiral Marcus intervenes, Kirk is kept on as Pike's first officer, while Spock is sent to another ship.
And during these scenes, it's made clear that Kirk and Spock are friends now, and Kirk is annoyed that Spock is showing no emotion about the prospect of their separation.
After the big library terrorist attack in London, Starfleet identifies the culprit as John Harrison, a Starfleet officer (though by some accounts, we soon realize this is just an identity he's assumed.) All of the top Starfleet brass meet to discuss the attack, and for some reason Kirk is there — Kirk keeps trying to tell them something, and they won't listen, until it's too late. Kirk realizes the only reason to attack a library is to lure all the Starfleet brass into one location to discuss it. Sure enough, Harrison attacks on a spaceship, killing all the top admirals and injuring Pike. Kirk finds a way to disable Harrison's craft, but Harrison looks him in the eye as he beams out.
Also, the lucky Brazilians saw some scenes where the Enterprise is damaged and crashing into the Earth. Spock, who's in command at this point, orders everybody to abandon ship. Sulu says that with all due respect, nobody is leaving their posts. Especially not while the ship is in danger of crashing into a populated area. Kirk and Scotty run to Engineering to try and stabilize the ship, leading to scenes of people being flung around corridors upside down and stuff.
And then they saw a glimpse of the scene we've seen in the trailers, where Spock beams down to a city, maybe San Francisco, and chases after John Harrison. They fight, Harrison jumps onto a spaceship that's flying by, and Spock chases after him. [Judao via AICN and Trek Movie]