This is the story of an adult brother and sister whose lives are indelibly marked by the deaths of their parents, killed in a car accident when the children were young.  Set in the small town in upstate NewYork where they grew up, the film centers on a visit by Terry (Mark Ruffalo) to his older sister Sammy (Laura Linney). Portraying the vicissitudes of their relationship, the film traces the effects of loss on these two compelling individuals.

The film opens uncoyly with the scene of the parents' fatal car accident. Beneath the credits we watch the church-funeral, the two small children clutching hands while a Minister addresses the assembled.  

When the story picks up, we are introduced to the lives of the now adult siblings.  Sammy is still living in their parents' home, working in a local bank branch office and raising her son Rudy, a somber eight-year old who is becoming curious about his estranged father.  Rudy, at eight, is the age Terry was when their parents died. Sammy is a reliable, loving mom, but otherwise her life appears constricted.

We find Terry, the younger brother who is now twenty-five years old, saying goodbye to a much younger girlfriend; he is leaving to borrow some money from his sister, whom he hasn't seen in two years.  Terry, endearing but irresponsible, is leading a marginal existence, broke and unemployed, no fixed address.

A long restaurant reunion scene between the siblings reveals the texture of their relationship. We see that Sammy adores and worries about Terry; he is the light of her life.  Terry conveys restless discomfort with his sister's expectations, experiencing her concern for him as a burden.  He reveals that he has been out of touch because he was in prison for a while, and that he needs to borrow money to pay for a girl's abortion.

After learning that his girlfriend has attempted suicide, Terry sends her the money and decides to stay with Sammy for a while. In small increments, Terry and his nephew Rudy warm up to one another.  Meanwhile Sammy's life takes an unexpected turn as she begins an affair with her controlling, married boss (Matthew Broderick); this begins just after an old flame of hers resurfaces with a marriage proposal.  Neither relationship provides her much nourishment. Without easy answers, the film helps us connect the dots between Sammy's unsatisfying relationships with men and her adaptation to loss and to becoming the caretaking elder sibling.  

Terry's visit goes wrong when, after a series of small irresponsible dealings with Rudy, Terry takes it upon himself to introduce the child to his estranged father, resulting in an ugly scene.  Sammy, distraught, asks her brother to leave, as he "doesn't know how to be around an eight year old."  The film ends with their farewell as they wait for Terry's bus out of town. Terry doesn't know where he is heading or when he'll be back. The scene presents a remarkable exchange of feelings as Terry comforts Sammy, telling her it's always good to know that she "is back here rooting" for him, and assuring her that "everything will be all right -comparatively."   Sammy cannot draw him into her world or her life, and every parting with him feels permanent. They find their childhood connection in this scene--and the camera follows each of them for several beats after they separate, Terry on the bus and then Sammy driving to work.  We feel them slowly absorbing the violence of severing--going back into themselves.  Have they affirmed that in fact they can count on one another or reminded themselves (and us) that nothing can be counted on?

A surprise element in the movie is the character of Father Ron, a Minister played by writer-director Kenneth Lonergan.  Sammy turns to the minister for guidance, seeking advice about her brother.  In two surprising scenes, Father Ron injects into the narrative a sweetly earnest note regarding faith and finding meaning in our lives.