This book contains two short stories about the Glass family. The first one concerns Franny, the youngest of the seven Glass children. In the second story, the main characters are Franny and her older brother Zooey, although the rest of the family is also introduced.

Away at school, Franny begins to have doubts about the meaning of life. Like Holden Caulfield in Catcher in the Rye, she is disgusted by the fake masks that others put on in public. Her agony seems to go beyond Holden's, however, and she turns to spirituality in search of a solution. She becomes obsessed with a book called The Way of the Pilgrim, in which a Russian peasant finds inner peace by repeating a simple prayer over and over again, until it literally becomes a part of him. Franny tries this procedure herself, until it leads to a nervous breakdown. But was the prayer the cause of her breakdown, or vice versa?

The second story, Zooey, begins with a hilarious scene of Zooey trying to take a bath with his mother constantly interrupting him. They are both worried sick over Franny, who is asleep in the living room, but they have markedly different approaches to handling the situation. Zooey is forever the comic, hiding his concern behind a string of witticisms and insults. But he has been down the same path as Franny before, and tries to use his experiences to help her. He blames Franny's breakdown, and some of his own problems, on their two oldest brothers. His more simple-minded mother, however, doesn't understand what her children are going through, but her love for them is clear. In the end, Zooey tries to bring Franny around with a deep discussion of his philosophy of religion, the meaning of life, and the Fat Lady.