This Iranian film is widely considered to be one of the front runners for this year's Foreign Film Oscar, and it is a fine piece of work.
It begins with a couple seated before a judge, asking him to resolve their dispute. Simin (Leila Hatami) has finally gotten visa papers that would allow the family to leave Iran, but Nader (Peyman Maadi) refuses to leave, as he is the sole caregiver for his father, who has Alzheimer's. Nader is not contesting Simin's request for a divorce; the sticking point is custody of the couple's ten-year-old daughter. Since they cannot agree on that issue, the judge refuses to grant their divorce.
Simin moves back to her mother's home, and Nader is forced to hire a woman to tend to his father during the day. Razieh (Sareh Bayat) finds the job more demanding than expected, and suggests that her husband Hodjat (Shahab Hosseini) could take over for her.
That sounds like a lot of plot, but it's only the first few minutes of the movie, and things haven't even begun to get complicated yet. The two couples eventually find themselves caught up in a painful legal battle in which gender, religion, and economic class all play key roles.
Those social issues are always present, and we're constantly being reminded of their impact on the story, but not in a heavy-handed way. The story comes first, and it will grab you and hold your attention from the opening scene.
Writer/director Asghar Farhadi doesn't give us an obvious rooting interest, and he does everything he can to maintain the ambiguity of the story. Scenes cut off just before important events; the questions that characters ask one another frequently go unanswered; almost everyone is eventually proven to be lying about something.
You can't easily lump A Separation into any particular genre; it's equal parts detective story, courtroon drama (in an Iranian way, which has a very different feel than an American proceeding would), and family drama. It's a movie in which we empathize with all of the main characters, even as we wince at the awful decisions they're making.