In the 1960s, Dr. David Banner was creating an idea to add on to the immune system, which General Ross declined to use since it is unethical to experiment on humans. David experimented on himself against Ross' protocol. His wife was conceived by his altered sperm and gave birth to Robert Bruce Banner by 1968. David researched his experiment and how the genes passed on to his son. By 1972, he plotted an attempt to explode his hometown and eventually kill his son. His wife, Edith got in the way. This resulted in repressed memories for his son, now known as Bruce Krenzler for the next thirty years as David stayed in prison.
Bruce Krenzler works at Berkeley Institute, with Betty Ross to test nanomeds and gamma radiation on frogs. The first test failed, resulting in a frog reduced to blood. During the aftermath, Bruce met Talbot, a narcissistic member of Atheon and a former military general. As Bruce began another test, his colleague Harper accidentally started the gamma radiation, which caused Bruce to get an amount of radiation. At the lab hospital, Betty paid a visit and worried how he could have died from the test. All of a sudden, Bruce encounters his real father, David and three dogs he has for test subjects. David explained that Bruce's surname is actually Banner and not Krenzler. Bruce felt angry from seeing his father, which made him become the Hulk and destroy a half of Berkeley, including the Gammasphere.
The morning after, Betty saw Bruce at her house and wondered what happened at Berkeley. Bruce later confronted General Ross, who knew what Bruce's heritage is. Betty visited David and talked about how he passed on his genes to his son. Hours later, David called Bruce and explained that he mutated his three dogs with his son's DNA and the nanomeds to become feral beasts. He also said that he sent them towards Betty. Talbot arrived, causing Bruce to get more anxious. This caused Bruce to go towards Betty and kill the three dogs.
After two exhausting nights, Bruce felt very worried about his "disease" while he talked to Betty. He was tranquilized by the General's soldiers and sent to a desert base. Meanwhile, David experimented on himself with his son's DNA and the nanomeds. Since he is elderly, he gained the ability to absorb everything he touched.
Talbot was seen psychologically torturing Bruce so the earlier can make an army based on Bruce's DNA. Bruce was put to sleep inside an underwater tank, but the repressed memories inside him made Bruce wake up and become the Hulk. He escaped the facility and ran towards the desert, the canyons and the Golden Gate Bridge, destroying military vehicles in the process.
Betty gently intervened so Bruce would calm down and see his father for one last time. David became delusional and upset, claiming the military is full of dictators, which made him bite into the electric cable and become a being of lightning. Bruce became the Hulk and followed his father to Pear Lake. David was able to absorb Bruce's energy, but it made him became a giant green bubble of memories. A missile sent by Ross killed David and left Bruce alive.
One year later, Bruce stayed in South America to help the poor and warned the paramilitary in the Spanish language that they wouldn't like him when he's angry.
While the film got number 1 at the first weekend at the box office, the film had polarized reception. Contemporary reviewers didn't like how the Hulk showed up rarely as well as the scenes of dialogue and visual effects. Over time, people have been more kind to the film that it is an analysis of psychodrama meshed with a superhero movie, which might have influenced future films such as The Dark Knight and Logan, which have similar bleak tones yet got more acclaim.