Esther is at the beach with her friend Jody, Jody's boyfriend Mark, and a boy named Cal, whom Jody told her she would like. Esther thinks that her mother asked Jody to suggest the outing, since otherwise all Esther does is sit in her room with the shades drawn. Esther and Cal discuss a play in which a mother debates whether to kill her brain-diseased son. Esther, who has now spend an entire month without sleep, still has suicide on her mind. She thinks drowning might be the kindest way to die; burning the worst. She goes off for a swim with Cal, but he gives up and goes back before they reach the rock that Esther has pointed out as the target.
Esther tells of how she had tried to hang herself that morning. She had wrapped a silk cord from a bathrobe around her head, but could find nothing in the house to attach the cord to. She knows she is mentally disturbed because she has made a point of reading books on abnormal psychology, and she thinks she is incurable.
As she swims to the rock, Esther decides to drown herself. She stops swimming and dives into the water. But each time she tries this, she comes straight back up again, and floats. Eventually she gives up and turns back to the shore.
At her mother's suggestion, she becomes a volunteer at the local hospital. She is put on the maternity ward and told to deliver bouquets of flowers that have been sent to the patients. She takes it upon herself to remove the dead and dying flowers and then rearranges them to fill out some of the vases that are now only skimpily filled. But the women patients complain to the nurse that they are not getting the flowers they were promised. Disturbed by this reaction, Esther runs away and does not return to the hospital.
She goes to visit her father's grave, where she has never been before. She has difficulty in finding it, but when she does she places flowers on it. Then she sits down and cries.
She finally decides on a suicide plan. She leaves a note for her mother saying that she has gone for a walk. She takes a bottle of sleeping pills and a glass of water and goes down into the cellar, where she hides in a crawl space. She takes all the pills and falls asleep.
Several days later, semi-conscious, Esther hears voices and briefly sees a light. She does not know it, but she has been found and is being rescued.
She finds herself in a hospital. One of her eyes is bandaged, but the doctor tells her that her sight is intact. Her mother and brother come to see her, and later she is visited by an old acquaintance named George Bakewell, who is the houseman at the hospital. Esther tells him to go away and not come back.
Esther asks the nurse for a mirror, but at first the nurse refuses, because, she says, Esther does not look very pretty. When the nurse does give her a mirror, Esther does not recognize herself. Her hair is shaved off, one side of her face is purple and misshapen, and the mouth is brown. She throws the mirror to the floor, breaking it. Two nurses rebuke her.
She is moved to a psychiatric ward in a city hospital. A young Italian woman in the next bed is initially friendly but stops talking to her when Esther tells her that she tried to kill herself.
Esther is visited by many young doctors. They consider her uncooperative, telling her mother that she will not talk to them and that she refuses to make anything in Occupational Therapy. She persuades her mother to try to get her out of the hospital. Meanwhile, Esther proves a difficult patient. She kicks an attendant who has mocked her and the other patients, and she deliberately knocks a tray of thermometers to the floor, to the annoyance of the nurses.
As Esther repeatedly tries to commit suicide, she is surprised by the fact that her body seems to have a will of its own to go on living, despite what her mind has decided she wants to do. When she tries to tighten the cord around her neck and strangle herself, her hands weaken and she lets go: "Then I saw that my body had all sorts of little tricks, such as making my hands go limp at the crucial second, which would save it, time and again, whereas if I had the whole say, I would be dead in a flash." In this sense she regards her body as an enemy, no more than a "stupid cage" that she is trapped in.
At the beach, as she swims out to the rock planning another suicide attempt, she hears her heartbeat booming in her ears. "I am I am I am," she interprets it as saying. The heartbeat represents the body's will to go on living, its steady affirmation of its own life.
The same will of the body to survive manifests when Esther tries to drown herself. No matter how hard she tries, her body keeps returning to the surface like a cork. In this respect, the body is showing itself to be stronger than the disturbed mind that seeks to destroy it.