Bruce Banner returns to S.H.I.E.L.D. for some help on Samuel Sterns, a.k.a. Project Mr. Blue, to study what is wrong with him, until he and Betty accidently shocked him hard, then Samuel Sterns becomes the code name of Mr. Blue, then he teams up with terrorists to try and destroy the Government and Washington.
- Mark Ruffalo - Bruce Banner, in the end, Leaves for Borneo, with Betty Ross!
- Lou Ferrigo - Hulk
- Jessica Biel - Betty Ross, in the end, Ashamed of her Father, leaves with Bruce!
- R. Lee Ermy - General Thaddeus Ross, in the end, stripped of his title of General and was sentenced life, for the Gamma accident which Banner was blamed for!
- Cobie Smulders - Maria Hill, in the end, arrests Ross!
- Joseph Gordon-Levitt - Rick Jones, a fan of the Hulk, in the end, keeps Hulk's whereabouts a secret!
- Ty Burrel - Doc Samson, becomes reduced to Gamma Radiation, in the end, helps Hulk beat Zzax!
- Angie Harmon - Jessica Walters/She-Hulk, in the end, helps Hulk beats Zzax!
- Tim Blake Nelson - Samuel Sterns/Mr. Blue/The Leader, the main antagonist, he plans to destroy the Government and wants control of the United States, in the end, states "I AM THE LEADER"!