Kennicott feels hurt that Carol does not show any interest in the town's boosting campaign. He protests that he will no longer bear Carol's rebellion against the town. Carol tells him that she does not belong to Gopher Prairie and wants to leave. For a month, they argue about Carol's decision to leave, hurting each other a great deal in the process of discussion. In October, Carol and Hugh take a train to Washington, D.C. Although Carol tries to play make- believe games with Hugh on the train, she sadly reflects that her practical and unimaginative son resembles his father. The town newspaper later announces that Mrs. Kennicott has gone to Washington to help out the war activities.

Carol finds employment in the Bureau of War Risk Insurance. She finds the office dull but enjoys the city life, especially the cultural attractions and beautiful buildings. She mixes with people who keep up on politics and contemporary social issues, unlike the people in Gopher Prairie. In particular, she makes many acquaintances with women in the suffrage movement. However, Carol also talks to many women from small towns who are currently living in Washington. Through them, she realizes that Gopher Prairie actually looks good compared to other small towns. Gradually, Carol realizes that she has tried to wage war against individuals rather than against larger institutions like the church and the country—the institutions that are really to blame for making a town like Gopher Prairie what it is.

After a year, Carol feels tired of office work. She encounters Percy Bresnahan in Washington, and a friend in the army tells her that many people consider Bresnahan a good salesman but an idiot who harasses the government and aeronautics section. At the movies, Carol recognizes Erik Valborg onscreen playing a bit part adequately, and feels sorry for him.

Thirteen months after her departure, Kennicott visits Carol in Washington. She feels touched seeing her husband all dressed up. She takes him sightseeing and introduces him to all her friends. He gives her news of Gopher Prairie and shows her photographs of the town, just as he had showed her photographs when he first courted her. However, Kennicott does not ask her to return. He only indicates that he would welcome her home but wants her to come back only if she really wants to do so. Carol replies that she does want to return to Gopher Prairie but still wants to feel free to criticize it.

Carol and Kennicott take a trip around the South, which he refers to as a "second wooing." He tries to confess about his affair with Maud Dyer, but Carol tells him not to say anything. Kennicott returns to Gopher Prairie alone, and Carol decides to return in a couple of months. Carol no longer feels hatred to the town, only sympathy and understanding. She decides that she must accept people as they are but will still continue to question everything. When Carol returns, she is pregnant with her second child.

When Carol returns to Gopher Prairie, she finds herself at home with the familiar faces. She also feels happy to have been missed by many of the townspeople who warmly welcome her back. However, she also realizes that nothing in Gopher Prairie has changed, except for a few building projects and a new school. She becomes active in town activities. One day, local men in a barbershop discuss Carol's return and decide to accept her.