Though they no longer live together, it’s hard to imagine two people closer than Natalie Swerdlow (Diane Keaton) and her daughter, Sara (Alexa Davalos).  With a relationship that centers on Sara’s lifelong love for The Wizard of Oz, these two women share every secret about the men in their lives at every chance they get.

While preparing for her annual summer pilgrimage to a beach house with her best friend, playwright Adam Goldman (Tom Everett Scott), Sara, a graduate student in Japanese, keeps Natalie abreast of their plans.  But after Sara, Adam, and their friends – Maddy (Lauren German) and her husband Peter (Josh Hopkins), and Adam’s new lover, Shawn (Chris Pine) – arrive at the ramshackle rental house, a cruel twist of fate forever changes their lives…and Natalie’s.

Tragedy strikes when, on their way back from an after dinner trip to pick up some ice cream,  a car accident that kills Sara leaves Adam with hardly a scratch.  Upon getting the devastating news, the grief-stricken Natalie heads for the shore and, following a funeral that is held without any of her daughter’s friends, surprises them when she arrives at their summer house.

In a veritable whirlwind of housecleaning, Natalie makes everyone uncomfortable, though no one more than Adam, who is sure she blames him for Sara’s death.  With no one having the nerve to ask her to leave, she reveals the extent to which she and Sara shared the intimate details of their lives, telling Peter that she knows about his affair with her daughter.  But it’s when Adam confesses to his friends that he is hiding Sara’s diary from her mom that Maddy stuns everyone when she lets slip that she and Sara once toyed with sex when they were in college.  However, still not done meddling in the lives of her late daughter’s friends, Natalie gets Shawn to admit that he’s been unfaithful to Adam.

Yet it’s when she invites herself along to a party at the home of producer Mel Wolfe (Peter Riegert) that Natalie really begins to get under Adam’s skin.  After encouraging Shawn to perform an impromptu audition for Mel, and then casually telling Adam about his boyfriend’s infidelity, some hallucinogenic mushrooms that belonged to Sara send Natalie into a drug-induced haze that parks a fight between Adam and Peter.  However, it’s when Peter tells Natalie that he paid for Sara to have an abortion after she became pregnant with his baby that the evening comes unglued.

After Mel uses Adam’s play as an excuse to track down Natalie at the summer house, Adam confronts Shawn and the tension begins to thaw.  But it’s when Natalie finally comes across the diary that Adam had been hiding from her – written entirely in Japanese -- that she finally finds the closure she’s been seeking.  While out with Mel at a Japanese restaurant, she convinces a chef to translate the diary and discovers that Sara found their relationship smothering and looked forward to the day when she didn’t have to divulge everything to her mom.  So, as she comes to grips with the truth, Natalie finally finds the courage to let go and, in doing so, makes amends with Sara’s friends.