Slaughterhouse-Five is an account of Billy Pilgrim's capture and incarceration by the Germans during the last years of World War II, and scattered throughout the narrative are episodes from Billy's life both before and after the war, and from his travels to the planet Tralfamadore (Trawl-fahm-uh-door). Billy is able to move both forwards and backwards through his lifetime in an arbitrary cycle of events. Enduring the tedious life of a 1950s optometrist in Ilium, New York, he is the lover of a former pornographic movie star on the planet Tralfamadore and simultaneously an American prisoner of war (POW) in Nazi Germany.
Vonnegut uses Billy's ability to travel in time as a device to evoke a wide range of scenes from Billy's life. The multidimensional panorama points out the importance of cyclical time and psychological experience during events that receive equal emphasis in linear time. While some scenes become so jumbled that they seem to have no cause or effect, we must remember Vonnegut's comments on the title page. He suggests that this narrative is "schizophrenic," and he invites us to become psychologists helping Billy make sense of his life.
Slaughterhouse-Five's central topic is the horror of the Dresden bombing. As a witness to the destruction, Billy confronts fundamental questions about the meanings of life and death. Traumatized by the events in Dresden, Billy can provide no answers. As a soldier, he is dislocated in a system where there is no reward, no punishment, and no justice. Although his life as an optometrist, a husband, and a father is materially fulfilling, he is unable to find peace of mind because of the trauma he suffered in Dresden.
Ultimately, Billy reconciles this trauma with the acceptance of the Tralfamadorian doctrine that there is no such thing as free will: Billy cannot change the past, the present, or the future. In the final analysis, Vonnegut suggests that life is like a simple, meaningless limerick, a nonsensical verse that never ends because it continuously repeats itself. At the beginning of Slaughterhouse-Five, the bird's song asks, "Poo-tee-weet?" at the end of the novel, Billy hears the bird still asking the same simple, meaningless question.