Madeline (Maddy) Whittier

An 18-year-old girl who lives in isolation due to Severe Combined Immunodeficiency (SCID). Maddy is the narrator and one of the book’s two main protagonists. She is an avid reader, is homeschooled, and has a very close relationship with her mother. She dreams of a life outside her house.

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The boy who lives next door to Maddy and the book’s other main protagonist. He wears only black clothing and practices parkour. He often wears an elastic band around his wrist. His family has moved around a lot, and Olly is very mysterious, although very protective of his mother and sister.

Read an in-depth analysis of Olly.

Pauline Whittier

Maddy’s mother, who lost her husband and son in a car accident when Maddy was five months old. She is Maddy’s primary care physician and spends all her free time with Maddy.

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Maddy’s nurse, who is dedicated to keeping Maddy safe and grows to love her like a daughter. She shows her affection openly and communicates clearly and directly. She fled Mexico as a young woman and risked everything to start a better life.

Read an in-depth analysis of Carla.

Olly’s Father

A businessman who used to be kind to his family, but developed a drinking problem after losing his job when Olly was a child. He has become increasingly violent and abusive, usually directing his aggression at Olly’s mother.


Olly’s dreadlocked friend who lives in Hawaii. He is gay and hopes to be a rock star, despite his parent’s objections. His parents are very traditional and possibly homophobic.

Olly’s Mother

A stay-at-home mother of two teenage children who caters to her husband’s every need. She is fearful of her abusive husband but does not dare to leave him.


Olly’s younger sister. She smokes cigarettes in secret and spends most of her time on her cell phone. She appears to be angry and disconnected most of the time. Olly is protective of her.


Carla’s 17-year-old daughter. She was very close with Carla until she matured and became interested in boys, after which she doesn’t spend much time with Carla.

Mr. Waterman

Maddy’s architecture tutor. He never pities Maddy, and he is her favorite tutor.

Janet Pritchert

The nurse who replaces Carla for Maddy’s care. Janet is unsmiling and has a shrill voice. She is alternately brusque and passive-aggressive in her communication.

Dr. Melissa Francis

The doctor who treats Maddy in Hawaii.

Dr. Chase

Maddy’s Severe Combined Immunodeficiency (SCID) specialist.

Maddy’s father

Maddy’s father, who was killed in a car accident when Maddy was a baby.

Maddy’s brother

Maddy’s brother, who was killed in a car accident when he was a young child along with Maddy’s father.