Although Ian McEwan's World War II-era novel "Atonement" is a powerful read, it's one of those literary works that doesn't seem intended to be translated to the screen. Not only is it dominated by minuscule dramas of perception and interpretation, but the narrator is an unlikable child whose ambitious, fanciful mind wreaks havoc on many lives.

Against those odds, screenwriter Christopher Hampton and director Joe Wright have turned McEwan's best novel into a fluid, sumptuous and thoroughly engaging drama.

The posters for the movie, with Keira Knightley and James McAvoy's beautiful faces gazing wistfully out of the frame, suggest that this is purely a romance. But while Knightley's Cecilia Tallis, a girl to the manner born; and McAvoy's Robbie, the son of her family's housekeeper (Brenda Blethyn), are indeed a star-crossed couple -- and vital to the advertising campaign -- "Atonement" is much more than a love story.

It's set in England on the eve of change, at a time when members of the ruling class, such as the Tallis family, clung to their power with particular tenacity precisely because it was starting to slip away. The youngest Tallis, 13-year-old Briony (Saoirse Ronan) is deeply emblematic of that power shift, privileged in every way and unable to imagine anything else. Her youth makes her particularly blind to possibilities beyond what she already knows. In McEwan's words, she is a child "possessed by a desire to have the world just so."

When Briony observes

her sister from a distance, engaged in a peculiar scene with Robbie, involving a vase, a fountain and ambiguous body language, her assumptions are based on class. Robbie is a servant and, therefore, as a man, he's a brute, or so she assumes (this is a child who writes plays of the highest romantic ideals).

In truth he's a bright Oxford graduate headed to medical school. But her rich imagination gallops off, and after a violent incident on the estate that evening, Briony fingers Robbie. War gets him out of prison, and the story takes him through the terrible spectacle of Dunkirk -- which includes the single most beautiful tracking shot in any movie this year -- while simultaneously following Cecilia's and a more grown-up Briony's (Romola Garai) volunteer work as nurses.

McAvoy ("The Last King of Scotland") comes into his own as a lead; and Knightley, costumed to the nines, gives her most mature performance to date. Benedict Cumberbatch is memorable as an slippery wealthy man; and Juno Temple is just right in the pivotal part of Lola, Briony's slightly older cousin.

Of the Brionys (three actresses play her), Ronan, with her pale, pointy face and sharp eyes, is the best cast. We see how much Briony intuits through the natural intelligence and curiosity of a born writer, but also that she is still a child. The combination is dangerous.

Despite these fine performances, what lingers afterward is the evocation of a mood. On that languid day in 1939 when the most important actions take place, typewriters clack, flies buzz and the heat sizzles. Wright makes us feel multiple perspectives: a couple plagued by the double heat of the sun and an unsettling attraction to each other; and a young girl, so convinced of her gifted mind's clarity that she believes she sees through all that heat.

The only weakness in the cinematic translation is in the ending. McEwan's last chapter unfolds in a startling revelation of regret, all told as if in a whisper from author to reader, that leaves you devastated. Even knowing what the outcome was, I was hit anew with the power of "Atonement's" rumination on responsibility and storytelling, but wishing that Wright had found a way to make it less abrupt and jarringly modern for the benefit of those who had not seen it on a page first.

Reach Mary F. Pols at mpols@bayareanewsgroup.com or 925-945-4741. Read her blog at http://www.ibabuzz.com/shortcuts.

'ATONEMENT'

GRADE: A-

Starring: Keira Knightley, James McAvoy, Saoirse Ronan, Brenda Blethyn, Juno Temple, Benedict Cumberbatch

Director: Joe Wright

Rated: R for disturbing war images, language and some sexuality

Opens today: Century 9, S.F.; Clay, S.F.; expands Dec. 14

Running time: 2 hours, 10 minutes