In the chapters 024.00-040.00 of Wintergirls, how and why does Lia change?
Between the chapters entitled 024.00 and 040.00, Lia's condition deteriorates. Haunted by the death of her childhood friend Cassie, Lia begins to starve herself, cheating to make it seem that she is fine on her weekly weigh-ins. Cassie had called Lia thirty-three times on the night she died, but Lia, angry at her, did not answer her phone. Overcome by feelings of guilt, Lia hallucinates that she is being visited by Cassie's ghost.
Lia's stepmother and father suspect that she is back to her self-destructive ways, but cannot prove it. Cassie's funeral is approaching, and Lia wants to attend, thinking that if she sees the casket put into the ground, her friend will stop haunting her. Lia prevaricates skillfully enough to convince her therapist and parents to allow her to attend the funeral. In reality, Lia continues to starve herself, and resumes her old habit of cutting as well. Attending Cassie's funeral does not stop Lia's hallucinations; if anything, it makes them worse.
Forced against her will to spend some time with her birthmother, Lia continues her downward spiral. She agrees to eat a meal in exchange for the truth about Cassie's death. Lia learns from her mother that Cassie died a terrible, lonely death, having ruptured her esophagus after a bout of drinking, binging, and purging. The image of her friend, alone and terrified in a motel room, exacerbates Lia's own tenuous condition. She returns to her father and stepmother's home, craving food but steadfastly denying herself, as her weight plummets towards the "danger zone."