Nora Davis (born Nora Nierling) is the protagonist of The Locked Door. She is a general surgeon living in Mountain View, California. Nora changed her name after the arrest of her father, serial killer Aaron Nierling, in order to distance herself from the scandal of his crimes. She is described as being in her “mid-thirties” (8) with “dark eyes” (86) and “jet black hair” (42), which she typically wears “in a tight bun that makes [her] hair follicles scream with agony” (11).

Nora is characterized by her desire to not be like her father. From the beginning, Nora is aware of “what it meant to be Aaron Nierling’s daughter” (217) and worries that “the apple doesn’t fall far from the tree” (65). These passages suggest that Nora believes she may have inherited her father’s violence. However, Nora makes an intentional decision “to live [her] life differently” (66), and she repeats the phrase, “I’m not like my father,” or “not like him” multiple times throughout the novel (37, 230, 286). Nora’s desire to distance herself from her father is reflected in her decision to change her last name from Nierling to Davis.

Nora is also characterized by her lack of emotional connections with others.