Set in the 1930s, Lionel Trilling’s novel explores the relationships between politics and friendship among upper-middle-class American intellectuals. The novel is primarily located at a Connecticut summer retreat.

When he takes the train there from New York to stay with friends, John Laskell talks with his old college friend, Gifford Maxim. Both men are entering an apparent mid-life crisis, although they are only in their early 30s. Laskell is just recovering from scarlet fever and his fiancée's death. His friends, Arthur and Nancy Croom, have invited him to spend much of the summer at their home. Maxim, in contrast, has been living a double life and believes that a crisis of conscience has prompted him to change his ways. A dedicated Communist, Maxim had been spying for the Soviet Union but has renounced his allegiance.

Arriving at the Crooms' house, Laskell finds himself in the middle of political squabbling between the Crooms, who are Party sympathizers, and Maxim. Nancy seems personally affronted by Maxim's change of position, and Laskell often must be the voice of reason. Their arguments concern religion as well, as the Crooms are agnostic and Maxim now declares himself a Christian.

Also visiting is Kermit Simpson, who publishes the liberal New Era journal; Laskell had been instrumental in getting Maxim a writing position there. Maxim is anxious to revindicate his reputation, but the Crooms do not believe that an anti-Communist crackdown is imminent. Arthur, an economics professor, and Nancy cling to their idealistic belief in the promise of the Revolution and their Marxist faith in the proletariat (of which their experience is largely through the workers at their home). In particular, they admire the handyman, Duck Caldwell, despite warnings that he is not just irresponsible—often drunk—but also violent.

Laskell, alienated from his hosts when they downplay the seriousness of his illness, seeks solace in an affair with Caldwell's wife, Emily. Her class-climbing aspirations are largely focused on her pre-adolescent daughter, Susan, whom she encourages to think not only of college but an elite women's school (such as Vassar).

Distrustful of her husband and protective of the girl, she never told him Susan has a heart condition. Duck's total lack of understanding for his wife and daughter flares up in an outburst: he lashes out and strikes the girl. Because of her heart condition, the blow proves fatal. The Crooms must finally acknowledge their myopia, and political issues recede before personal tragedy.