Rowan Caine is the 27-year-old main character. The book is primarily told from her perspective through a letter she writes to a lawyer named Mr. Wrexham, imploring him to represent her in her upcoming murder trial. Rowan is a nanny who has been accused of murdering one of the children in her care. She explains that she’s in Charnsworth, a Scottish women’s prison, waiting for her trial to begin. She is English and describes herself as “visibly middle class” (12), especially when compared to the other prisoners. Even though she initially feels as though she is above the other women in the prison, she finds that, over time, her appearance has hardened. Her eyes are dark like “chips of granite” (13) and her face is “white” (13) and firmly set. The letter only briefly mentions Rowan’s current imprisonment before backtracking to recount her short-lived tenure as a nanny for the Elincourt family. Her primary goal is to prove her innocence to Mr. Wrexham in the murder of Maddie Elincourt, one of the Elincourts’ four daughters.

Notable aspects of her personality include a propensity for anger and deep-seated resentment towards her mother. She eventually reveals that she has been using a false identity, and her real name is Rachel Gerhardt.