Note: Billy Pilgrim, the novel’s protagonist, has become “unstuck in time.” He travels between periods of his life, unable to control which period he lands in. As a result, the narrative is not chronological or linear. Instead, it jumps back and forth in time and place. The novel is structured in small sections, each several paragraphs long, that describe various moments of his life.

Billy Pilgrim is born in 1922 and grows up in Ilium, New York. A funny-looking, weak youth, he does reasonably well in high school, enrolls in night classes at the Ilium School of Optometry, and is drafted into the army during World War II. He trains as a chaplain’s assistant in South Carolina, where an umpire officiates during practice battles and announces who survives and who dies before they all sit down to lunch together. Billy’s father dies in a hunting accident shortly before Billy ships overseas to join an infantry regiment in Luxembourg. Billy is thrown into the Battle of the Bulge in Belgium and is immediately taken prisoner behind German lines. Just before his capture, he experiences his first incident of time—shifting: he sees the entirety of his life, from beginning to end, in one sweep.

Billy is transported in a crowded railway boxcar to a POW camp in Germany. Upon his arrival, he and the other privates are treated to a feast by a group of fellow prisoners, who are English officers who were captured earlier in the war. Billy suffers a breakdown and gets a shot of morphine that sends him time-tripping again. Soon he and the other Americans travel onward to the beautiful city of Dresden, still relatively untouched by wartime privation. Here the prisoners must work for their keep at various labors, including the manufacture of a nutritional malt syrup. Their camp occupies a former slaughterhouse. One night, Allied forces carpet bomb the city, then drop incendiary bombs to create a firestorm that sucks most of the oxygen into the blaze, asphyxiating or incinerating roughly 130,000 people. Billy and his fellow POWs survive in an airtight meat locker. They emerge to find a moonscape of destruction, where they are forced to excavate corpses from the rubble. Several days later, Russian forces capture the city, and Billy’s involvement in the war ends.

Billy returns to Ilium and finishes optometry school. He gets engaged to Valencia Merble, the obese daughter of the school’s founder. After a nervous breakdown, Billy commits himself to a veterans’ hospital and receives shock treatments. During his stay in the mental ward, a fellow patient introduces Billy to the science fiction novels of a writer named Kilgore Trout. After his recuperation, Billy gets married. His wealthy father-in-law sets him up in the optometry business, and Billy and Valencia raise two children and grow rich. Billy acquires the trappings of the suburban American dream: a Cadillac, a stately home with modern appliances, a bejeweled wife, and the presidency of the Lions Club. He is not aware of keeping any secrets from himself, but at his eighteenth wedding anniversary party the sight of a barbershop quartet makes him break down because, he realizes, it triggers a memory of Dresden.

The night after his daughter’s wedding in 1967, as he later reveals on a radio talk show, Billy is kidnapped by two-foot-high aliens who resemble upside-down toilet plungers, who he says are called Tralfamadorians. They take him in their flying saucer to the planet Tralfamadore, where they mate him with a movie actress named Montana Wildhack. She, like Billy, has been brought from Earth to live under a transparent geodesic dome in a zoo where Tralfamadorians can observe extraterrestrial curiosities. The Tralfamadorians explain to Billy their perception of time, how its entire sweep exists for them simultaneously in the fourth dimension. When someone dies, that person is simply dead at a particular time. Somewhere else and at a different time he or she is alive and well. Tralfamadorians prefer to look at life’s nicer moments.

When he returns to Earth, Billy initially says nothing of his experiences. In 1968, he gets on a chartered plane to go to an optometry conference in Montreal. The plane crashes into a mountain, and, among the optometrists, only Billy survives. A brain surgeon operates on him in a Vermont hospital. On her way to visit him there, Valencia dies of accidental carbon monoxide poisoning after crashing her car. Billy’s daughter places him under the care of a nurse back home in Ilium. But he feels that the time is ripe to tell the world what he has learned. Billy has foreseen this moment while time-tripping, and he knows that his message will eventually be accepted. He sneaks off to New York City, where he goes on a radio talk show. Shortly thereafter, he writes a letter to the local paper. His daughter is at her wit’s end and does not know what to do with him. Billy makes a tape recording of his account of his death, which he predicts will occur in 1976 after Chicago has been hydrogen-bombed by the Chinese. He knows exactly how it will happen: a vengeful man he knew in the war will hire someone to shoot him. Billy adds that he will experience the violet hum of death and then will skip back to some other point in his life. He has seen it all many times.