Entertainment Weekly's second annual Comic-Con preview package features Iron Man 2 on the cover, and inside it's jam-packed with exclusive first looks at highly anticipated TV shows and movies. After Iron Man blasted Robert Downey Jr. back to stardom, the superhero returns to the big screen to battle new villain Mickey Rourke, size up Scarlett Johansson, and prove the first time wasn't a fluke. The success of Iron Man (which opened at $99 million and went on to take in $318 million) caught many people by surprise, and now four months later, Downey is no longer the underdog. "There are a lot more invisible eyes on us now," he says.

When Marvel Studios first announced the sequel, no one was sure what the movie would be about. Downey, director Jon Favreau, screenwriter Justin Theroux, and the rest of the creative team struck upon the idea of introducing two very different foes for Stark. On one side is Justin Hammer (Sam Rockwell), a fast-talking weapons manufacturer who fancies himself the next Tony Stark; on the other, Vanko, who, while incarcerated in a Russian prison, creates his own battle-suit, which shoots devastating, whip-like beams. Hammer and Whiplash join forces to take Downey's character Tony Stark down. Rourke, for his part, wanted to instill some lightness into the role of the heavy. "I told Favreau, 'I don't want to just play him as a one-dimensional p----,'" Rourke says. "He let me have a cockatoo, who I talk to and get drunk with while I'm making my suit."

Just as the deals were being hammered out, Terrence Howard - who had played Stark's best friend - fell out of the sequel in a public salary dispute. The role was re-cast, with Don Cheadle stepping in. "We had to make some tough deals," Marvel Studios president Kevin Feige says. "When they got public, you go, 'That sucks. OK, you want a peek behind the curtain? Here you are!'" Says Cheadle, "Terrence and I couldn't be more different. We address it head-on in the movie in one exchange. We're not trying to fool people."(Cheadle admits he didn't know much about Marvel's superhero before the first movie came out: "I always thought Iron Man was a robot.")

Adding more flesh and blood to the new movie, Scarlett Johansson joined the cast as Stark's mysterious new assistant, Natasha, who has an alter ego of her own, Black Widow. That introduction inevitably sparks romantic tension between Stark and former assistant Pepper Potts (Gwyneth Paltrow), who's been promoted to CEO of Stark Industries. "The men want it to be, like, 'Ooh, the girls are fighting over Tony,' but it's not as standard as that," says Paltrow. "There's a weird male catfight fantasy." Downey doesn't disagree: "Our signature as a superhero franchise is that we're horny. Not, like, can't-bring-your-kids horny, but just...horny."

With these new ingredients, the question remains whether Iron Man 2 will soar like the first film or show signs of rust when it hits theaters next May 7. "People are going to be more critical," says Downey. "That's their prerogative....In a way, there's no way to win, except to win. Big." (Cover Story, Page 24)