Wintergirls is a young-adult fiction novel written by Laurie Halse Anderson about best friends Lia and Cassie. The two girls have been friends for years, through thick and thin. In a cruel twist of fate, both girls have developed eating disorders. The story jumps back and forth between the present and memories of the time Lia and Cassie spent together as Lia tries to make sense of her best friend's death. Cassie struggled with bulimia nervosa and was found dead in a motel room after a binge-purge episode that caused her stomach to essentially tear open. In the days leading up to her death, Cassie had tried reaching Lia by phone several times, but Lia did not pick up. Lia feels intense guilt because she feels she might have been able to prevent her friend's death, but would it have been worth risking her own safety?
In order to reconcile her guilt and try to make sense of Cassie's death, Lia tries to follow in the steps she took over the last few days of her life. Lia tracks down the motel Cassie died in and visits the room, even trying to sleep there. Lia has been haunted--both literally and figuratively--by Cassie's ghost and her own troubles with self-harm. In the motel room where Cassie died, Lia takes a handful of sleeping pills and goes to sleep. When she wakes up in the hospital, Lia realizes that she wants to live, despite her failing to be there for Cassie and in spite of the sorrow they shared. By retracing Cassie's steps and having her own near brush with death, Lia is able to move on from her trauma.