In a suburb of Chicago, Illinois, in the late 2000s, Shelby Tebow is at home with her baby. Her husband, Jason, comes home. Jason makes excuses for his late arrival, but Shelby knows he is having an affair. After the baby goes to sleep, Shelby leaves, pretending she is going for a run. Instead, she texts a man she knows as Sam, one of several men she hooks up with from time to time. As she walks toward their appointed meeting place, Shelby feels she is being followed and wonders whether Jason believes her lies. When she bends to tie her shoe, a car appears, moving quickly.

Kubica omits the names of the characters in the prologue; we only come to understand who they are later.

Content Warning: This section mentions child abuse and neglect.

Eleven years later, a sixteen-year-old girl, who believes herself to be Delilah Dickey, lives in captivity in a pitch-dark basement. In reality, the girl is called Carly Bird, though Kubica conceals this from the reader. Carly describes how her captors, Eddie and Martha Cutter, whom she refers to as “the man” and “the lady,” rarely feed or clean her. Martha verbally abuses and neglects Carly. Though Eddie treats her more kindly, the novel implies that he is either sexually abusing or grooming her for abuse.