After being discharged from a mental hospital, Stella Shaw returns to university with her pet cat, hoping to lead a quiet life as her doctor advised. However, she encounters a group of cruel and savage roommates. They start by attacking Stella's appearance and forbidding her from keeping the cat, then slander her character, mock her family of origin, and intentionally sabotage her relationships. Finally, they poison her, damaging her vocal cords in an attempt to destroy her dream of singing... These experiences gradually break down Stella's fragile psychological defenses, causing her illness to relapse. In the end, betrayed by her boyfriend, with her cat injured and her dreams shattered, she can no longer bear it and snaps, taking mad revenge on everyone who bullied her.
