However, Sam is not dead. Captured and tortured by the Taliban, he is eventually forced to commit a horrific act— killing a fellow soldier —to survive. When he is finally rescued and returns home, he is a hollow shell of his former self, consumed by guilt and paranoid suspicion regarding Tommy and Grace.
When Sam is rescued and returns home, he is a changed man, suffering from severe PTSD. He is uncharacteristically withdrawn, volatile, and deeply suspicious that Grace and Tommy have had an affair. Brothers (2009) - Plot - IMDb
Arun’s nightmares returned. He began to see their father’s clean hands—calloused but careful—binding ropes in the dark, and a shadow handing him a brown envelope. He remembered the night their mother packed a single blanket and told him to look after his brothers. “No debts,” she had said, though everyone knew debts never disappeared, only traveled.