Sam Cahill (Tobey Maguire) is a marine captain going on his fourth tour of duty. He is a level-headed family man. He married his high school sweetheart, Grace (Natalie Portman), and has two young children, Isabelle and Maggie. Just before Sam departs for Afghanistan, his brother Tommy (Jake Gyllenhaal) is released from jail.
Though word comes that Sam's helicopter crashed, killing everyone on board, in reality, he and Joe Willis, were taken prisoner. Meanwhile, Tommy tries to rehabilitate himself by getting friends to help repairing the Grace's kitchen. Grace slowly loses her former animosity against Tommy.
Over time, Grace and Tommy become close because of their shared grief, ultimately resulting in a kiss. They regret it afterwards and do not take their mutual attraction further than that. Meanwhile, Sam and Joe are tortured by their captors. The captors eventually think Joe useless and force Sam to kill him with a lead pipe. Afterwards, Sam gets rescued.
Sam returns home a changed man. He is emotionally closed off to the rest of the world and refuses to explain what happened in Afghanistan. He believes Tommy and Grace have had a sexual relationship in his absence. At one point, an irritable Isabelle says that Sam's paranoid accusations are true. Sam gets furious. He destroys the remodeled kitchen and pulls a gun on Tommy, who tries to calm him. The police arrive, and after a confrontation in which Sam nearly commits suicide, he eventually surrenders.
Sam is put in a mental hospital. Grace goes to see him and threatens to leave him if he doesn't tell her what happened in Afghanistan. Sam finally opens up, telling her that he killed Joe. A letter is read aloud, with Sam wondering if he will still be able to have a normal life.
Best part of story, including ending:
It's a story about how war affects people.
Best scene in story:
Where Grace and Tommy kiss but decide not to take it any further.
Opinion about the main character:
He is a captain but he doesn't see he needs help.