Kaysen's fellow patient and the effective leader of the girls on the ward. Lisa is proud of her diagnosis as a sociopath, a personality driven by self-interest. Lisa is wildly unpredictable. She throws tantrums and plans escapes for others when she isn't making her own attempts to escape. Kaysen is initially in awe of Lisa's apparent confidence. Over time, though, she learns that Lisa cares little for the consequences of her actions and can be willfully cruel.