Set in December 2003, Larry “Doc” Shepherd (Steve Carell) visits the bar of Sal Nealon (Bryan Cranston), a former Marine that he served with in Vietnam. After introducing himself, Doc, a Navy corpsman briefly mentions his bad-conduct discharge and subsequent incarceration in the US Navy prison. The next morning, Sal and Doc drive to the church of another friend from Vietnam, Richard Mueller (Laurence Fishburne), where he is the pastor. At Mueller’s house that evening, Doc reveals that his wife had recently passed away, and the purpose of his trip was to ask his friend to accompany him to retrieve and bury his son, Larry, who had recently been killed in Iraq. Sal agrees, while Mueller is initially reluctant to leave; at the insistence of his wife he eventually agrees and they begin the trip to Washington DC.
Along the way, Sal expresses his frustration in Mueller, who had been referred to as The Mauler in Vietnam for frequently hiring prostitutes, for his reformation and religious adherence. Conversely, Mueller expresses his disappointment that Sal has not matured since they had last seen each other in Vietnam. Upon arriving at Dover Air Force Base, Doc requests to view the body of his son, against the advice of LtCol. Willits (Yul Vazquez). Sal and Mueller are led away by LCpl. Charlie Washington, Larry’s close friend that was with him when he died. Charlie reveals that Larry had been killed while shopping at an Iraqi market, contrary to the official story of dying while fighting heroically. Doc is distraught after seeing his son’s body, and subsequently learns the truth about how his son died. Against the advice of Willits, Doc demands to take his son’s body and bury him in his hometown of Portsmouth, New Hampshire, rather than Arlington National Cemetery. Sal and Mueller leave to rent a U-Haul truck to carry the coffin, and reveal their abuse of Doc’s morphine supply in Vietnam resulted in a painful death of a fellow Marine and Doc’s bad conduct discharge. After renting the truck, Mueller is dropped off at a bus station, intending to return home. After loading Larry’s coffin into the truck, Doc and Sal are stopped by Security Forces, as Mueller is simultaneously apprehended by the Department of Homeland Security. The men are released, and Willits admits that their false apprehension came from a suspicious report by the rental agent at U-haul. The three men agree to allow the government to transport Larry’s coffin by train to New Hampshire, accompanied by Charlie.
Doc, Sal, and Mueller disembark in New York City, and subsequently miss their train. While at dinner, they discuss the death of Jimmy Hightower, the fellow Marine who was unable to get any morphine. The following morning, they catch a train to Boston, where Sal arranges to meet Jimmy Hightower’s mother. Intending to come clean about her son’s painful death, the three men realize that she believes the story that Jimmy died heroically while saving others, and continue to support that story.
Arriving in Portsmouth, Doc, Sal, and Mueller reconnect with Charlie, and prepare for Larry’s funeral. Doc, upset with the government for lying about his son’s death, intends for Larry to be buried in a suit. At Charlie’s insistence, Larry will be buried in his uniform. At the burial ceremony, Sal and Mueller wear their uniforms, and participate in the flag-folding ceremony. Back at Doc’s house, Charlie gives Doc a letter from Larry, revealing that he wished to be buried next to his mother in uniform, and thanking Doc for his parenting.