On one side is Justin Hammer (Sam Rockwell), a fast-talking weapons manufacturer who fancies himself the next Tony Stark; on the other, Vanko (Mickey Rourke), 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.

Adding more flesh and blood to the new movie is Stark's mysterious new assistant, Natasha, who has an alter ego of her own, Black Widow (Scarlett Johansson). That introduction inevitably sparks romantic tension between Stark and former assistant Pepper Potts, who's been promoted to CEO of Stark Industries.