Bruce Banner is hiding in Brazil, working in a juice factory while (a) learning to control his anger, and (b) searching for a cure for his condition, collaborating via Internet using his laptop with an American scientist code-named Mr. Blue.
When General Thunderbolt Ross gets a lead on Banner, he dispatches a commando team led by expert soldier Emil Blonsky to capture him. At first, Bruce manages to elude his captors but when he is cornered by the soldiers and the local bullies, he turns into the Hulk, smashes up the factory and escapes.
Back in the States, Ross recruits Blonsky as a test subject for a super-soldier project involving the Hulk formula. Bruce contacts his former girlfriend Betty Ross at her University and recovers the pen drive containing the data on his experiments.
The army, including a stronger, faster Blonsky, intercepts him; Bruce turns into the Hulk again and beats them, protecting Betty from a crashing helicopter. He then leaps away with Betty in his arms.
When the Hulk becomes Bruce again, Betty helps him contact the mysterious Mr. Blue, who turns out to be New York biologist Samuel Sterns, and sends him the data.
This transaction also allows the army to pick up his trail and head for New York as well.
Sterns, who has been experimenting with the Hulk's DNA, manages to inject Bruce with a serum that stops his transformation into the Hulk, leaving him unable to defend himself when the army captures him.
Blonsky, drunk with the power the serum has given him, forces Sterns to inject him with the Hulk's blood.
Blonsky is transformed into a bigger, uglier, meaner monster, the Abomination and goes on a rampage through the streets of Harlem.
Bruce, realizing he's the only one who can stop the new monster, leaps out of the helicopter; the shock of the fall turns him into the Hulk on landing.
The two giants clash in the streets of New York. The Abomination has the upper hand because he is stronger than the Hulk, but in the end, the Hulk beats down his foe.
Jade Jaws then bounds away.
Later we find Bruce Banner in hiding in the Canadian wilderness, able to control the monster within him.