Billy and Roland are captured by a group of five Germans engaged in a "mopping up" operation. Two teens, two old men, and one middle aged commander, they aren't exactly fearsome. The Germans take Roland's weapons and boots, and march Billy and Roland to a cottage filled with other American soldiers. Billy falls asleep and travels in time to awaken in his optometry practice in 1967, having fallen asleep while examining a patient. Shortly after, Billy closes his eyes and returns to the cottage in the war, being kicked awake by a German. The Americans are marched away by the Germans, while a photographer takes pictures of Billy and Roland's feet, and staged photos of Germans "capturing" Billy.

     Returning to 1967, Billy drives to a Lions Club meeting through Ilium's black ghetto, and the burned and dilapidated buildings remind him of towns he saw during the war. During the Lions Club meeting, a major in the US Marines speaks about the Vietnam war, and how increased bombings of North Vietnam are needed. Billy is introduced to the major later, who tells Billy he should be proud of his son for serving as a Green Beret in Vietnam.

     After the lunch, Billy goes home to take a nap, as his doctor has ordered him to do, because Billy sometimes cries for no reason. Billy's wife and daughter have left a note that they are out shopping, and Billy lies in bed to sleep, but cries instead. After closing his eyes, Billy is once again in the war, marching with the other captured Americans. As they continue to walk, they are merged with more and more prisoners to form a massive group. Groups of reserve German soldiers pass the American prisoners, and Roland Weary, who has been forced to wear painful clogs, becomes increasingly angry at Billy for bumping into him.

     Eventually the Americans are marched from Luxembourg into Germany, where they will be loaded into boxcars separated by rank. Billy is crammed into a car with other privates, most of whom are very young besides a former hobo who is forty years old. He tells Billy that he's been hungrier and in worse places than this. Men in another car call out that a man has died, but the Germans retire to their own car, which Billy can see has bunks with quilts, a stove, and hot food. Eventually the soldiers come out to retrieve the dead man, Wild Bob, who had a high fever before he was loaded into the car, and had spoken to Billy as if he was one of his former regiment.

     While other trains leave the yard, Billy's doesn't move for two days. The cars remain locked during this time, and food and water are passed through the ventilators to the prisoners, They use steel helmets for excrement, which are passed to Billy to dump them out. The men take turns standing up and lying down, and on Christmas Eve, while nestled to sleep beside the hobo, Billy travels in time to the night of his daughter's wedding in 1967.

     After the wedding, Billy is in bed with his wife, but cannot sleep and gets out of bed. Knowing that he will soon be kidnapped by a flying saucer, Billy drinks champagne and watches a movie about American bombers during the war, but sees it backwards, so that planes appear to suck bullets out of each other, and return to America to have their weapons removed and safely buried in the ground. Billy goes outside to meet the saucer, and he is enclosed in a cylinder of purple light, compelled by a zap gun to hold on to a ladder that is lowered from the saucer.

     Once aboard, Billy asks the Tralfamadorians why they have chosen him, and their answer is that they are all bugs trapped in the amber of the moment. Billy is then anesthetized by the Tralfamadorians and regains consciousness back on the train crossing Germany during the war.

     Billy tries to lie down to sleep, but none of the other men want him anywhere near them, saying he kicks and yells in his sleep, so he sleeps standing up or not at all. At this point, food has stopped being passed to the men, and on the ninth day, the hobo dies. In a separate car, Roland Weary also dies from gangrene that spread from his feet. Before he dies, he tells everyone that Billy is responsible for his death.

     On the tenth day, the train reaches a camp for prisoners of war. Billy is given a coat from a frozen pile of coats that belonged to dead soldiers, and goes through a delousing station, during which he travels in time. First, Billy is an infant after his mother has bathed him, then playing golf in his middle age, and then aboard a flying saucer. Billy asks the Tralfamadorian where he is and how he got there, and the Tralfamadorian responds that they are bound for a time warp to Tralfamadore, explaining to Billy that Tralfamadorians see all time as existing at once and unchanging. When Billy comments that the Tralfamadorian must not believe in free will, it responds that of all the planets in the universe, only on Earth is there talk of free will.