Joe Wright’s adaptation of Atonement works—and also doesn’t work—on nearly an identical level. As a piece of film craft, it’s undeniably impressive, the kind of movie that gathers Oscar nominations by the score. But at times, it presents itself as though auditioning for its own CliffsNotes: an ambitious, thoughtful, thoroughly literary story that practically dares you not to recognize that it is Art.

The story opens in 1935, at the English country estate of the Tallis family. Oldest son Leon (Patrick Kennedy) is returning for a visit, and the household is in a tizzy preparing for his arrival. But Leon’s younger sister Cecilia (Keira Knightley) and the housekeeper’s son Robbie (James McAvoy) are preoccupied by an unexpected mutual spark of attraction after being acquainted for years. And Cecilia’s 13-year-old sister, budding writer Briony (Saoirse Ronan), is about to become preoccupied with both intercepting a risqué letter from Robbie to Cecilia, and catching them in a compromising position she’s not quite old enough to understand.

While the film is covering these events in its first act, it’s a surprisingly gripping drama. Director Joe Wright (the 2005 Keira Knightley version of Pride and Prejudice) backtracks deftly through the narrative at key moments, filling in key pieces of the incomplete picture Briony sees. He also employs one of the most fascinating musical choices in recent years: a spare instrumental score by Dario Marianelli that turns the staccato smack of typewriter keys into its principal percussion. Every choice—the crispness of an edit, the darkness of a scene’s lighting—feels so controlled that Atonement seems well on its way to greatness.

Flash forward four years in the characters’ lives—and suddenly the momentum is lost. Robbie finds himself a soldier wandering through France towards the Dunkirk evacuation; Cecilia has become a nurse; and an older Briony (Romola Garai), whose actions separated the two would-be lovers on that fateful night in 1935, has come to understand her tragic error. But somehow the grand, sad wartime romance that Atonement wants to be never quite emerges. Wright gets distracted by staging the kind of epic, “How did he do that?” multi-minute tracking shot of Dunkirk beach that draws more attention to its own technical virtuosity than to any dramatic necessity. Neither Knightley nor McAvoy has a chance to let a character evolve, and the tightly wound tension of the film’s first 45 minutes comes unraveled.

The shame of it is that, thematically, McEwan and Wright are visiting some interesting territory. Atonement delves into the “truth” of storytelling, and the times where a convenient lie serves a more crucial purpose than honesty. Garai gets a terrific scene with a wounded French soldier, as Briony compassionately plays the role the confused man has set out for her. But even as the story explores how words both wound and heal, the consequences remain more theoretical than concrete. Briony can’t fully understand what her actions have cost Cecilia and Robbie—and neither, unfortunately, can we.

Atonement closes with a coda casting Vanessa Redgrave as a present-day Briony, now a novelist being interviewed about her latest book—coincidentally, one based on the story we have just seen. Her comments re-cast much of what has gone before, but the revelations don’t pack nearly the wallop that they should; they rely too much on dramatizations that remind us once again how little we actually know about Cecilia and Robbie. In a film with several brilliant individual moments, the characters serve as place-holders for a thesis. Atonement turns into the perfect sort of movie you might write an analytical paper about—and not quite the sort of movie you love.

ATONEMENT