The text centers on Billy's capture by the German Army and his survival of the Allied firebombing of Dresden as a prisoner of war, an experience that Vonnegut endured as an American serviceman.

Billy believes that an extraterrestrial species from the planet Tralfamadore held him captive in an alien zoo and that he has experienced time travel.

The two of them are captured in 1944 by the Germans, who confiscate all of Weary's belongings and force him to wear wooden clogs that cut painfully into his feet; the resulting wounds become gangrenous, which eventually kills him.

While Weary is dying in a rail car full of prisoners, he convinces a fellow soldier, Paul Lazzaro, that Billy is to blame for his death.

During Billy's stay at the hospital, Eliot Rosewater introduces him to the work of an obscure science fiction writer named Kilgore Trout.

On Barbara's wedding night, Billy is abducted by a flying saucer and taken to a planet many light-years away from Earth called Tralfamadore.

The Tralfamadorians later abduct a pornographic film star named Montana Wildhack, who had disappeared on Earth and supposedly drowned in San Pedro Bay.

The aliens trick the abductees into thinking they are managing investments on Earth, which excites the humans and, in turn, sparks interest in the observers.

After a Maori New Zealand soldier working with Billy dies of dry heaves the Germans begin cremating the bodies en masse with flamethrowers.

Billy is eventually killed in 1976, at which point the United States has been partitioned into twenty separate countries and attacked by China with thermonuclear weapons.

In keeping with Vonnegut's signature style, the novel's syntax and sentence structure are simple, and irony, sentimentality, black humor, and didacticism are prevalent throughout the work.

[8] Like much of his oeuvre, Slaughterhouse-Five is broken into small pieces, and in this case, into brief experiences, each focused on a specific point in time.

He uses it as a refrain when events of death, dying, and mortality occur or are mentioned; as a narrative transition to another subject; as a memento mori; as comic relief; and to explain the unexplained.

[10] The narrator explains that Billy Pilgrim experiences his life discontinuously, so that he randomly lives (and re-lives) his birth, youth, old age and death, rather than experiencing them in the normal linear order.

Bergenholtz and Clark write about what Vonnegut actually means when he uses that saying: "Presumably, readers who have not embraced Tralfamadorian determinism will be both amused and disturbed by this indiscriminate use of 'So it goes.'

JC Justus summarizes it the best when he mentions that, "'Tralfamadorian determinism and passivity' that Pilgrim later adopts as well as Christian fatalism wherein God himself has ordained the atrocities of war...".

Having experienced all of these horrors in his lifetime, Pilgrim ended up adopting the Christian ideal that God had everything planned and he had given his approval for the war to happen.

This juxtaposition is displayed throughout the book, rather directly asking the reader to confront the logical absurdities inherent in both Christian faith and Tralfamadorianism.

In the words of one writer, "perhaps due to the fact that PTSD was not officially recognized as a mental disorder yet, the establishment fails Billy by neither providing an accurate diagnosis nor proposing any coping mechanisms.

Fictional novelist Kilgore Trout, often an important character in other Vonnegut novels, is a social commentator and a friend to Billy Pilgrim in Slaughterhouse-Five.

Another bumper sticker is mentioned, reading "Impeach Earl Warren," referencing a real-life campaign by the far-right John Birch Society.

[34] Critic Tony Tanner suggested that it is employed to illustrate the contrast between Billy Pilgrim's and the Tralfamadorians' views of fatalism.

Vonnegut had told this to friends earlier, but waited until after he learned that both of Crone's parents were deceased to publicly disclose this information.

[37][38] Edgar Derby, killed for looting a teapot, was modeled on Vonnegut's fellow prisoner Mike Palaia, who was executed for plundering a jar of food (variously described as beans, fruit, or cherries).

[43] Slaughterhouse-Five has been the subject of many attempts at censorship due to its irreverent tone, purportedly obscene content and depictions of sex, American soldiers' use of profanity, and perceived heresy.

The Kurt Vonnegut Memorial Library countered by offering 150 free copies of the novel to Republic High School students on a first-come, first-served basis.

[54] In 2024 the book was banned in Texas by the Katy Independent School District on the basis that the novel is "adopting, supporting, or promoting gender fluidity"[55] despite also pronouncing a bullying policy that protects infringements on the rights of the student.

For Anthony Burgess, "Slaughterhouse is a kind of evasion—in a sense, like J. M. Barrie's Peter Pan—in which we're being told to carry the horror of the Dresden bombing, and everything it implies, up to a level of fantasy..." For Charles Harris, "The main idea emerging from Slaughterhouse-Five seems to be that the proper response to life is one of resigned acceptance."

For Alfred Kazin, "Vonnegut deprecates any attempt to see tragedy, that day, in Dresden...He likes to say, with arch fatalism, citing one horror after another, 'So it goes.'"

[57] When confronted with the question of how the desire to improve the world fits with the notion of time presented in Slaughterhouse-Five, Vonnegut responded "you understand, of course, that everything I say is horseshit.