Collins adapted the novel for film herself, in collaboration with screenwriter Billy Ray and Ross. The screenplay remains extremely faithful to the original novel, with Ross saying he "felt the only way to make the film really successful was to be totally subjective", echoing Collins' presentation of the novel in the first person present. Ross felt that, to preserve the novel's first person point of view, the audience could know little more than what protagonist Katniss Everdeen knows about the story's developments. Instead of presenting Katniss' internal monologues about the Capitol's machinations through actual monologues or voice-over narrations, the screenplay expanded on the character of Seneca Crane, the Head Gamemaker, to allow several developments for which Katniss is not present to be shown directly to the audience. Ross explained, "In the book, Katniss speculates about the game-makers' manipulations ... in the film, we can't get inside Katniss's head, but we do have the ability to cut away and actually show the machinations of the Capitol behind the scenes. I created the game centre and also expanded the role of Seneca Crane for those reasons. I thought it was totally important." Ross also added several scenes between Crane and Coriolanus Snow, the elderly President of Panem, noting that "I thought that it was very interesting that there would be one generation [of Panem citizens] who knew that [the Games] were actually an instrument of political control, and there would be a successive generation who was so enamoured with the ratings and the showbiz and the sensations and the spectacle that was subsuming the actual political intention, and that's really where the tension is". The Gamemakers' control center, about which Katniss can only speculate in the novel, was also developed as a location, helping to remind the audience of the artificial nature of the arena. Ross commented, "so much of the film happens in the woods that it's easy to forget this is a futuristic society, manipulating these events for the sake of an audience. The look of the control center, the antiseptic feeling of it and the use of holograms were all intended to make the arena feel 'constructed' even when you weren't seeing the control room." Ross and visual effects supervisor Sheena Duggal were keen to use the omniscient view that the setting provided to justify the literal dei ex machina Katniss experiences in the arena; Duggal explained that "we