Atonement, director Joe Wright's adaptation of Ian McEwan's 2001 novel of the same name, is, on the surface, a WWII British love story. Briony, an adolescent upper-middle-class girl in the interwar period makes a terrible error in judgement when she accuses her older sister Cecilia's lover (and the household gardener), Robbie, of rape. The consequences of her actions play out over the course of the film, with devastating results for all involved.
But while Atonement works -- quite well, I might add -- as an interwar, class-inflected tragedy, the film's true power is as a metafiction about the power (and impotence) of narrative. The film, like the novel, unfolds in four parts: a tense and lengthy prologue that culminates in the original lie being told; a melancholic intermission that follows Robbie's years at war in France; a third act that details Briony's work in a Red Cross hospital; and an unexpected epilogue that centers on an elderly Briony, now a successful author, discussing her most recent work. It was this epilogue that many viewers found frustrating, as Briony's novel is the story of her sister and Robbie, rewritten to give them the happy ending that they never had (but that the filmgoer had already experienced as the true outcome of their affair). The metafictional aspect of McEwan's novel, as well as Wright's film, is contained within bounds of the title and the epilogue -- Atonement, both the novel and the film, is fundamentally Briony's story, the writing of which is her atonement for her terrible mistake. By remaking the end, Briony attempts to give her Cecilia and Robbie the happiness her actions denied them in life; it is up to the reader, or the viewer, to decide whether or not the power of narrative extends so far into the realm of morality.
So what does all of this have to do with sound design? The first sounds we hear in Atonement are winding and slow taps of a typewriter. Tick tick tick, and the title card appears on a black screen.
The rhythm of the typewriter recurs throughout the entire first act of the film, sometimes buried underneath emphatic and swirling strings and piano, but always the only percussion apparent in the soundtrack. Moreover, the sounds of the typewriter move between the non-diegetic and diegetic modes, flowing easily from the soundtrack to the sound of the typewriter in Briony's bedroom. Every scene where Briony's perspective overwhelms the narrative, the typewriter arrives, either in the soundtrack or in the film itself. It disappears for the length of the second intermission, but re-emerges when the film centers itself once again on Briony, who works on her novel in the middle of the night.
The shift between diegetic and non-diegetic sound is also evident in the most celebrated scene of the film, the lengthy tracking shot of the army at Dunkirk. Here the soundtrack opens up to make space for the singing of a choir of the wounded as the camera pans across them; as it moves on, their voices fade again into the background.