Slaughterhouse-Five is the now famous parable of Billy Pilgrim, a World War II veteran and POW who has, in the later stage of his life, become "unstuck in time" and who experiences at will (or unwillingly) all known events of his chronology out of order and sometimes simultaneously.

Traumatized by the bombing of Dresden at the time he had been imprisoned, Pilgrim drifts through all events and history, sometimes deeply implicated, sometimes a witness. He is surrounded by Vonnegut's usual large cast of continuing characters (notably here the hack science fiction writer Kilgore Trout and the alien Tralfamadorians, who oversee his life and remind him constantly that there is no causation, no order, no motive to existence). The "unstuck" nature of Pilgrim's experience may constitute an early novelistic use of what we now call post-traumatic stress disorder; then again, Pilgrim's aliens may be as "real" as Dresden is real to him.

Struggling to find some purpose, order, or meaning to his existence and humanity's, Pilgrim meets the beauteous and mysterious Montana Wildhack (certainly the author's best character name), has a child with her, and drifts on some supernal plane, finally, in which Kilgore Trout, the Tralfamadorians, Montana Wildhack, and the ruins of Dresden do not merge but rather disperse through all planes of existence.

Slaughterhouse-Five was hugely successful, brought Vonnegut an enormous audience, was a finalist for the National Book Award and a best seller, and remains four decades later as timeless and shattering a war fiction as Catch-22, with which it stands as the two signal novels of their riotous and furious decade.