The film opens with a shot of a woman riding in a sport motorboat in Hawaii shortly before the credits roll and Matt King (George Clooney) narrates. Matt is a wealthy lawyer descended from Hawaiian royalty and white missionaries. He is the sole trustee of 25,000 acres of untouched land on the island of Kaua’i, passed down from his ancestors. The trust will expire in seven years, and the family has decided to sell the land to Don Hollitzer for development. Just as the family agrees on the deal and moves to sign, Matt’s wife Elizabeth is in a boating accident and rendered comatose. King explains how ridiculous it is that his friends on the mainland think Hawaii is a paradise when Matt has been living in a “paradise” full of UV and urination bags by her bedside. It is now clear that the woman in the opening shot is, in fact, Matt’s wife.
Matt and Elizabeth have two daughters, 10 year old Scottie (Amara Miller) and 17 year old Alex (Shailene Woodley). The elder attends boarding school on the Big Island. Matt is not very close with them and has spent very little time with them over the years. With Elizabeth in the hospital, Matt is forced to confront Scottie’s swearing and bullying and Alex’s alcohol problems. Matt learns that Elizabeth will not be waking up from her coma. Matt tells Alex, but not Scottie, that Elizabeth is not coming out of her coma. He tells her they will need to go around and tell friends and family about what is going on. Alex refuses and bluntly tells her father that Elizabeth was having an affair at the time of the accident. Matt is shaken and frantically jogs to the home of his and Elizabeth’s friends: Kai and Mark. Matt confronts them and demands information on his wife’s extramarital affair. Kai is reluctant to reveal anything and Matt angrily berates her and tells her that Elizabeth is going to be taken off of life support. Kai begins to cry and Matt leaves. Mark follows him outside and tells him the name of Elizabeth’s lover is Brian Speer. Matt leaves and cries on the side of a road.
Back at home Matt goes to tell Alex to get ready to go see her grandparents. He is surprised to see that Alex has a visitor: Sid (Nick Krause). Alex insists that Sid come with them and Matt grudgingly allows it. At Elizabeth’s parents’ house, Matt’s father in law Scott (Robert Forster) berates Matt and Alex and tells them that they put Elizabeth through hell. He punches Sid in the face after he laughs at Elizabeth’s mother, who suffers from dementia. On their way home Alex spots a real estate sign with a picture of Speer. Matt calls the number and finds out that Brian is on vacation. Matt, Alex, Sid, and Scottie travel to Kaua’i to search for him.
After a day or two relaxing and bonding on Kaua’i, Matt is jogging on the beach he passes a man that he realizes is Brian Speer. Matt trails him and sees him enter a cottage where his wife and two children are waiting. The cottage is owned by one of Matt’s cousins Hugh (Beau Bridges). Matt later speaks with Brian’s wife Julie (Judy Greer) while her children are swimming. He learns that Brian is a friend of his cousin’s and has something to do with the land deal. Later, cousin Hugh tells him that Brian is Don Holitzer’s brother in law and if Matt and his family decide to sell the land to Holitzer, Brian Speer is the one who stands to gain a fortune from commissions. Matt is shocked by this and decides to confront Brian Speer at the cottage. Matt confronts Brian while Alex distracts Julie.
When they arrive, Matt introduces himself as Elizabeth’s husband. Matt tells him that he isn’t there to cause any harm, just to let Brian know that Elizabeth is going to die in a few days and that he just wants to give him a chance to say goodbye. Brian says he loves his wife and his family and that he is truly sorry for everything. Matt asks if Elizabeth ever told Brian she loved him. He nods his head. Matt then asks Brian if he loved Elizabeth. Brian just stares at him without saying anything. It is clear to Matt that Brian was having an affair with Elizabeth in order to get closer to him, seeing as he is the sole trustee of the land. Matt exits the cottage and prepares to leave, but in a spontaneous moment kisses Julie. Matt, Alex, Scottie, and Sid are next seen on a plane going home, at which time Matt acknowledges the fact that Scottie is still unaware of her mother’s condition.
Back at home, Matt is at the meeting with his cousins, including Hugh, to vote on what will become of the 25,000 acres. As expected, the majority vote for Don Holitzer. Just as Matt is about to sign the papers, he has second thoughts and decides to keep the land. Shocked, Hugh threatens Matt and tells him that he and the other cousins will come after him.
At the hospital, Elizabeth is close to dying. Everyone says goodbye and a surprise visitor arrives. It is Julie Speer, now fully aware of the affair between Elizabeth and her husband. Julie begins to cry and stands over Elizabeth saying that she has to forgive her even though she wants to hate her for destroying her family. Matt tells Julie to leave. Alex and Scottie say their final goodbyes. Matt kisses Elizabeth one last time, and says “goodbye my love, my friend, my pain, my joy, goodbye” as tears roll down his face. Some time later Matt, Alex, and Scottie are in a small boat scattering Elizabeth’s ashes in the ocean.
The final shot shows Matt, now a single parent, with Alex and Scottie on the couch watching TV and eating ice cream as the credits roll.