The first half hour of Atonement director Joe Wright’s Anna Karenina is such a joy to watch, I began to doubt my expectations of the story. This has a tragic ending, doesn’t it? Terrible things are going to happen? For that matter, unfortunate things are happening in the first act, but the clever way they’ve been pieced together is a magical distraction, and appropriately so. Anna (Keira Knightley)’s brother, Oblonsky  (Matthew Macfadyen, hidden under one hell of a moustache) has cheated on his wife, the pretty, sweet Dolly (Kelly Macdonald), and Dolly doesn’t want to forgive him — so in swoops Anna, a cheery presence despite her loveless marriage to Karenin (Jude Law). Anna tells Dolly that if she doesn’t choose to forgive, she will make herself and Oblonsky miserable. Their happiness is in her hands; never mind that she did nothing to deserve that choice.

This Karenina is not exactly subtle. Wright sets nearly all of the action inside a worn theater; the stage is a bedroom, a racetrack, a ballroom. For the first act, this makes a marvel: Actors walk through doors into other settings without regard to the time that must have passed from one scene to the next; the theater’s seating area becomes a train station or Oblonsky’s office, where rows of men stamp papers with mechanical precision as Oblonsky walks through, changing coats as he goes, talking to idealistic Levin (Domhnall Gleeson) all the while. All that movement and magic makes Karenina begin like a musical without singing, carefully choreographed and bursting with energy that has nowhere to go. 

But two things let down this enrapturing first act: The theater setting starts to fall aside, to become less key, and cuts between scenes become more traditional, less dependent on clever sets and ingenious, compelling transitions. The magic seeps out; you can still see the footlights, but the sense of containment has been handed over to the late-19th century society, and even someone who’s never read Karenina can see that this is far more obvious, and far less interesting. 

Also less interesting is poor Anna, and her poor, meant-to-be-ever-so-handsome Vronksy (Aaron Taylor-Johnson), whose silly mop of blonde hair gives him a disconcerting resemblance to a prettier Borat. Taylor-Johnson is rather miscast; his sultry expressions provide little heat, and he lacks chemistry with Knightley, who’s wound so tightly that you expect her to go off more dramatically than she eventually does. Their burning desire for one another is far less convincing than society’s disdain for Anna’s choice. The quiet flame that Levin holds for Kitty (Alicia Vikander), the young girl who grows into a kind woman, is so much more effective that Levin becomes even more sympathetic than intended. 

Partly, perhaps, Knightley isn’t quite up to the task at hand, but Tom Stoppard’s adaptation fails her, fails to make Anna into a human and not just a symbol for society’s tight constraints on women (Oblonsky’s affair is between him and his wife, but Anna’s is the talk of the town). Anna Karenina drags in the middle and rushes to its ugly end — one too heavily foreshadowed by the frost-covered trains that race into scenes — but the sets, the choreography, the glorious costumes and the secondary characters (including a brilliantly cool Olivia Williams as Countess Vronsky) are pieces of a superior film. 

ANNA KARENINA: Directed by Joe Wright. Screenplay by Tom Stoppard, based on the novel by Leo Tolstoy. Cinematography, Seamus McGarvey. Editor, Melanie Oliver. Music, Dario Marianelli. Production designer, Sarah Greenwood. Starring Keira Knightley, Jude Law, Aaron Taylor-Johnson, Matthew Macfadyen and Kelly Macdonald. Focus Features, 2012. R. 129 minutes. Three Stars.