At the beginning of the book, Madeline’s life is defined by avoiding risks to her health, which is viewed by everyone as incredibly fragile and worth preserving at any cost. Pauline, Madeline, and Carla all work together to keep her “safely” inside, and Madeline unquestioningly complies with the rules that govern her life. As the book progresses, however, Carla comes to advocate for more freedom and less fear, helping Madeline secretly meet with Olly. She says, “Everything’s a risk. Not doing anything is a risk” (68), an apparent reversal of the philosophy previously at work in the house.

Because Olly represents the unknown, the outside world, and because he exudes a physicality that contrasts with Madeline’s intellectual outlook on the world, Madeline views him as a risk: “He’s the biggest risk I’ve ever taken” (69). Being involved with him, she believes, may lead to sickness and death—physical risks—but also to heartbreak and abandonment—emotional risks. She gradually concludes that the emotional risk of being alone forever outweighs the physical risk of illness or death. In fact, she is exhilarated by the physical “dangers” she undertakes as she leaves home, like jumping off cliffs, getting in the ocean without knowing how to swim, and having sex with Olly.