Jimmy Cross is a twenty-two-year-old lieutenant who serves in the Vietnam War. He leads his men through the villages of Than Khe. Martha, a college student back in the States, sends Jimmy letters and photographs detailing her life. Jimmy frequently fantasizes about a life with Martha but quickly realizes that although he loves her, she does not love him back. He spends most of his mental energy agonizing over Martha and their potential future. Out in the countryside of Vietnam, Jimmy leads his men through dark times. Each of his men carries something unique — a Bible, condoms, M&Ms — but they all carry the weight of the war. One of Jimmy's men, Ted Lavender, is particularly fearful. One day, as the platoon prepares to bomb the tunnel systems near Than Khe, Ted Lavender is shot and killed as he comes back from a pee break. As Jimmy's men inspect Ted's body and prepare him for evacuation, Jimmy can't help but think of Martha. Disgusted and guilt-ridden, Jimmy burns all of Martha's letters and photographs and vows to be a more stern lieutenant.