Spoiler alert: for educational purposes, this annotation reveals plot lines and may interfere with some viewers' enjoyment of the film. In the opening scene, Juliette (Kristin Scott Thomas), looking ashen, drawn, and nervous, sits in an airport as her much younger and radiant sister Léa (Elsa Zylberstein) rushes to meet her.  Léa brings an eager, if somewhat forced cheer to their halting conversations during this meeting and in their car ride to the home Léa shares with her husband, their two small adopted Vietnamese daughters, and her mute father-in-law.  From this awkward beginning, the sisters try to cross the chasm of a fifteen-year separation.  The cause and nature of the separation gradually unfold in small, slowly paced scenes of ordinary life at home, at work, in a café, during dinners with friends.  These scenes form the visible surface under which secrets and plangent, unacknowledged emotions lie, sometimes erupting into view, sometimes gently suggested.
    
The cause of the separation is the prison term Juliette has served in England.  We eventually learn that the sentence has to do with the death of her child, with her being a physician, with her child's suffering from cancer, and with the application of her medical knowledge to end his pain.  Following the court sentence, Juliette's parents refuse to acknowledge her, her husband divorces her, her sister buries memories of their childhood and chooses not to give birth, family and friends never visit her in prison.  We also learn that Juliette remained inexplicably silent throughout her trial.  She continues to say very little as she settles in with Lea's family and circle of friends, who are baffled by her sudden appearance in Lea's life.  But as Juliette's participation in her sister's circle increases in fitful starts, she becomes cautiously more communicative and brighter.

During a confrontation with Léa at the end of the film, Juliette reveals that, more than avoiding a shameful appraisal from others, she remains silent because there are no words to express her pain.  Being in prison made literal the isolating psychological state she inhabited.  "The worst prison is the death of one's child," she says.  "You never get out of it."  With these words, the film places the wound and the pain at the core of its main character in the inescapable vulnerability of motherhood.