Willowdale is a city located in the state of Virginia.
The project, initially thought to be researching radiation resistance, had the purpose of duplicating the results of the Project Rebirth developed during World War II, triggering the whole process with the use of Gamma Radiation. General Thaddeus Ross, father of Betty Ross, was the military overseer of the whole project.
Banner, being confident that their research was worthy enough to take the risk, decided to test a combination of their replica of the Super Soldier Serum and high doses of Gamma Radiation. However, the amount of radiation caused instead a violent non-permanent transformation into a giant, green-skinned, muscle-bound humanoid who went to become known as Hulk], a transformation that woud be triggered by anger and emotional stress. Hulk, driven by fits of extreme rage, destroyed the laboratory and injured both Thaddeus and Betty Ross.
General Ross, with a broken arm as a result of Banner's first transformation, met Banner again at the local hospital three days after the accident, offering him to take him to a military laboratory in Maryland while trying to visit Betty Ross. Banner, refusing Ross' conditions and blaming himself for all the people hurt during the incident, run off, evading the troops sent by General Ross in order to chase him.
Bruce Banner eventually returned to Willowdale years after his first transformation, to retrieve all data regarding the project in an attempt to cure himself of his conditions. Banner first tried to enter Culver University, but heavy security measures have been implemented since his departure, so he had to devise a new plan.
While walking through the campus, he could not help approaching the Biological Sciences Building, and check on Betty Ross, watching her without being sighted, and realizing she started a new relationship with Leonard Samson.
Banner sought refuge at a pizza restaurant owned by an old friend Stanley Lieber, who always knew that Banner was not the criminal General Thaddeus Ross made everyone believe. Banner disguised himself as a pizza delivery boy to infiltrate Culver University, tricking a Security Guard to gain access to his former laboratory, experiencing flashbacks of the incident.
However, all data about the project had been erased, and contacted the man who was helping him through his research of a cure, codenamed "Mister Blue", to inform him of the setback.
Betty Ross and Leonard Samson went to Lieber's pizza restaurant that same night to have dinner, and Banner, thinking Lieber was alone, almost entered the dining hall when he returned to the restaurant. Realizing that Betty saw him for an instant, Banner hid in the nearby alley, hoping that Betty believed it was her imagination.
Lieber revealed the truth watching Betty emotionally overwhelmed, and she went after Banner, finding him under the rain, embracing him and begging him not to leave anymore. Both returned to Betty's house, when she revealed that she held a copy of the investigation, without knowng that her father, General Thaddeus Ross, wanted to analyze Banner's body and reproduce the experiment to transform it into a weapon.
In order to protect Betty from danger, Banner decided to leave Willowdale the next day. However, Leonard Samson informed General Ross of Banner's presence, and a heavy operation was put together to capture Banner.
Banner realized that they were being observed, and tried to run from a large group of soldiers led by an enhanced Emil Blonsky and commanded by General Ross himself. Banner took advantage of his knowledge of the universy, and hid to swallow the USB containing the data about the project, in order to protect it if he was captured.
Betty tried to convince his father to leave Banner alone, but as they were speaking, Banner was trapped inside a elevated hallway, where the soldiers tried to render him unconscious using gas grenades. Instead, the stress of the situation triggered his transformation into Hulk.
General Ross let his daughter witness Hulk to convince her of the importance of his capture, and a ferocious battle between Hulk and the United States Armed Forces began. Hulk was able to neutralize the heavily armed soldiers and vehicles, resisting their attacks without being harmed.
Romanoff, startled by Banner's transformation, called Fury to receive orders about how to proceed. Fury simply demanded to not let Ross take Banner, either dead or alive.
Blonsky was ordered to act, approaching Hulk confident that his enhancements with a Super Soldier Serum would help him confront the green giant. Hulk used two pieces of debris to shield himself of the grenades shot by Blonsky. Blonsky was able to evade the attacks and lured his opponent to a pair of Stark Sonic Cannons, that almost subdued him.
Hulk was moved by Betty's pleas and overcame the sonic attacks. Blonsky approached Hulk again, taunting him despite Ross' direct orders, and Hulk defeated him with a single kick that crushed most of Blonsky's bones.
A helicopter opened fire over Hulk while Betty was approaching him, and Hulk protected her from harm, throwing his remaining debris to bring down the helicopter, shielding her again from the ensuing explosion that rendered her unconscious. Hulk escaped with her to the Smoky Mountain National Forest.
Ross confiscated all the data and evidences he could find in his daughter's house, and thanked Samson for informing him of Banner's presence. Samson showed remorse of his actions, as Banner only tried to protect Betty, even after his transformation, and noticed that Ross was lying when he affirmed that Betty's safety was his main concern.