In ''Brothers," a Danish Army major named Michael Lundberg (Ulrich Thomsen) picks up his younger sibling Jannik (Nikolaj Lie Kaas) from jail the day his sentence for robbing a bank ends. Michael is patient, conscientious, communicative, moral, clean-shaven, and empathic; he wants Jannik to call the woman he assaulted at the bank and apologize. His brother is a bearded, drunken mess.
Piercingly co-written and directed by Susanne Bier, the movie dramatizes one man's collapse and the other's surprising maturation.
Before he leaves for a tour of duty in Afghanistan, Michael plays with his two young daughters (Sarah Juel Werner and Rebecca Logstrup Soltau, both very good). And he says goodbye to his beautiful wife, Sarah, played by Connie Nielsen, who's far less clenched in a Danish movie than she was in ''Gladiator" and ''Basic."
Michael isn't on the case for a day when, in a handsomely photographed scene, his chopper is hit and crashes into a lake. His family has a funeral, tears are shed, and lives move on. But on the day of her husband's service, Sarah says she doesn't think Michael is dead. I found this too ponderous to take seriously, because up to this point ''Brothers" has been too absorbingly earthbound to turn into a pile of ''Ghost."
Then something remarkable happens, something that makes you believe in Sarah's marital sixth sense. Michael is pulled ashore, thrown into the bed of a truck, and tossed into a bunker, where he is the hostage of sadistic Afghans.
We're shuttled between scenes of the now-incarcerated brother and the recently freed one, who has finished the kitchen renovation Michael started and who has begun bonding with his sister-in-law and nieces. Directing from a script she wrote with Anders Thomas Jensen, Bier refuses to bog the picture down in a soapy romance between Sarah and Jannik. The current of attraction that passes between them is handled with delicate restraint.
The movie doesn't truly establish what it's up to until Michael comes home, lugging a case of post-traumatic stress disorder and jealous suspicion about what Sarah and Jannik have been up to in his absence. Without saying much more, the family's universe is turned upside down.
Bier is a graduate of Lars von Trier's Dogme school of cinematic constraint, but her movies don't dote on formal conceits, though they do pack an emotional wallop.
Her last film, 2002's ''Open Hearts," was also a triumph of grit over melodrama. That movie could have wrung more impact out of its setup -- the wife of a man paralyzed in a car crash falls in love with the husband of the woman who hit him. But ''Brothers" is a beautifully considered marvel of screenwriting. The film is about the irony of a simultaneous change in two selves: One brother can look at the other, and can suddenly see the man he once was, retreating in a rearview mirror.
Before long, Sarah starts to show the bewilderment her mother-in-law (Solbjorg Hojfeldt) exhibits after having been married to a man (Bent Mejding) who has berated everyone for not being as upstanding as Michael. Thomsen, who also played the returning son in ''The Celebration," exudes an initial goodness that makes Dad's preference easy to understand.
The character's homecoming is a grimmer story. What war does to Michael is sad. What Michael does to his family is sadder. And gradually, we hurt for a handful of people who two hours ago were strangers to us.
Wesley Morris can be reached at firstname.lastname@example.org.