The story begins with a chaotic scene when the protagonist has attempted suicide after a nervous breakdown. She denies her actions, claiming she had just taken the pills for a simple headache. However, it soon becomes clear that she is depressed. She is then sent to a mental institution after an interview with a doctor.
She befriends many of her fellow patients like Polly, Georgina, Daisy, and Lisa in her journey to recovery. While she has an attachment to all of them, she has a strange sense of adulation for Lisa. It is due to Lisa that she defies the institution and resists therapy.
The protagonist has a bittersweet relationship with the other patients. Sometimes she shows kindness, and sometimes her attitude borders on rudeness. Along with her friends, she plays quite a few pranks and gets caught in the institution a number of times. At one point, she pushes it to such an extreme that she runs away with Lisa, an event that leads to the suicide of Daisy.
This event shocks her into reality and she realizes that she truly does want to heal. So, she starts taking her meds seriously and takes a positive approach to therapy. However, just before she is about to be released, there is a confrontation between Lisa and her, and Lisa has stolen her diary to humiliate her in front of the others. While she screams and taunts Susanna, she finally pushes her off the edge. This confrontation ends in Lisa almost attempting suicide. Susanna goes to see Lisa one last time before she leaves the institution narrating that Lisa does ultimately get better.
