Kien has become Missing-In-Action in the fallout of the Vietnam War. He is tasked with the clean up and treatment of the bodies and remains of bodies in the Jungle of Screaming Souls. In the aftermath of the recently ended war, Kien and his friends attempt to forget the horrors and atrocities they have witnessed, all while literally burying the dead.
But Kien is not actually still in 1975. Rather, he has returned to his nearly apocalyptic experiences of trauma for the specific purpose of finishing his novel. It has been forty years since the war ended, but Kien can re-experience it all as if he were still there. Kien remembers the devastation the war brought to his community. His father abandoned hope, burned his paintings and died. Phuong sacrificed herself for Kien's life after Hoa raped her. He remembers the hosts of soldiers in the bars following the war, drinking to erase the traumatic memories, taking prostitutes in Hanoi.
Kien explains that he's not sharing all this for nothing; he's trying to capture the horror of war, because he feels the reader will likely not understand how terrifying it really was. He shares battle stories and writes about the deaths of his loved ones and comrades.
After a considerable exposition from Kien, Bao Ninh introduces himself to the reader (in the book, of course). Bao explains that he has been working with Kien to finish the novel, and although Kien has departed form this life, Bao explains that Kien's decision to finally look into his own traumatized past yielded a reward for Kien in this final days of his life: He remembered the way things used to feel when they were all naive and innocent, before the war.