"reboot" and "sequel", was a "perfect" description for the film. Norton explained his decision to ignore Lee's origin story: "I don't even like the phrase 'origin story', and I don't think in great literature and great films that explaining the roots of the story doesn't mean it comes in the beginning." "Audiences know this story," he added, "[so] deal with it artfully." He wanted to "have revelations even in the third act about what set this whole thing in motion". The new origin story references Ultimate Marvel's take on the Hulk, which also had him created in an attempt to make super soldiers. Norton removed Rick Jones and toned down S.H.I.E.L.D.'s presence. He also added the scene where Banner attempts to extract a cure from a flower and his e-mailing with Samuel Sterns, which references Bruce Jones' story. Norton rewrote scenes every day. Ultimately, the Writers Guild of America decided to credit the script solely to Penn, who argued Norton had not dramatically changed his script. Journalist Anne Thompson explained "The Guild tends to favor plot, structure and pre-existing characters over dialogue." Penn said in 2008, "I wasn't happy with [Norton] coming to Comic-Con saying that he wrote the script." Before either Penn or Norton joined the project, an anonymous screenwriter wrote a draft and lobbied for credit. Filming Leterrier had to direct four units with a broken foot. Filming began on July 9, 2007. Shooting primarily took place in Toronto, because mayor David Miller is a Hulk fan and promised to be very helpful to the crew when closing Yonge Street for four nights in September to shoot Hulk and Blonsky's climactic fight. Despite messing up the street with explosives and overturned burning vehicles, the crew would clean it up within twenty minutes so business could continue as normal each day. The first action sequence shot was the Culver University battle, which was filmed at the University of Toronto and Morningside Park. The filmmakers built a glass wall over a walkway at the university for when the soldiers trap Banner inside to smoke him out. There was also shooting in the Financial District. A factory in Hamilton, Ontario, which was due for demolition, was the interior of the Brazilian factory. The site's underground floors were used for Ross's military command center. The crew also shot part of the Hulk and Blonsky's fight on a backlot in Hamilton. Other Canadian