Rachel is a philosophy lecturer whose breast cancer recently went into remission. She lives in suburban Massachusetts and struggles financially following a divorce. Driven by fierce maternal instinct, she puts aside her ethical boundaries and academic background to meet extreme demands. She is forced to commit criminal acts to ensure her daughter's survival.

Kylie is Rachel and Marty's thirteen-year-old daughter. She is observant and resourceful, using her knowledge of the local area to try and track her location despite being blindfolded. She remains alert in captivity and actively looks for ways to free herself from her constraints.

Pete is an ex-Marine, Marty's brother, and Kylie's uncle. He possesses a specific set of tactical skills involving weapons and breaking into properties. He struggles with an opiate addiction that occasionally impairs his judgment, though he remains fiercely loyal to Rachel and Kylie.

Heather works as a college administrator and leads an outwardly normal life. She engages in extreme criminal behavior solely to secure the safety of her own child. She maintains a harsh and focused demeanor during stressful events, deeply unnerving her husband.

Marty is a lawyer, Rachel's ex-husband, and Kylie's father. He presents well in social situations and appears intelligent but often lacks situational awareness. Circumstances force Rachel to keep him entirely in the dark about the severe threats facing their family.

Jared is an English teacher who nervously assists his wife with a kidnapping. He is visibly unnerved by his own actions and tries to provide his captive with amenities like snacks and books. He struggles to cope with the severe personality changes his wife exhibits.

Amelia is an imaginative eight-year-old girl. She has a severe peanut allergy requiring an EpiPen. She initially believes her strange situation is an elaborate game before growing frustrated and demanding to return home.

Erik is a math professor at MIT who previously survived a severe family trauma. He uses his background in mathematics and systems decoding to track burner phone signals and analyze anonymous communication networks.

Ginger is an FBI agent pursuing a doctoral degree in Criminal Psychology. She meets Marty while jogging and soon becomes his romantic partner. She maintains a polite exterior while integrating into Marty's family life.

Olly is Ginger's twin brother and a software engineer. He is highly rational and methodical. He frequently worries about logistical complications and potential risks in his professional life.

Daniel is a retired police officer and an avid hunter. He lives in a house filled with hunting trophies and teaches his grandchildren how to handle firearms and clean animals.

Tom is a law enforcement officer who works for the FBI. He struggles with severe anger issues and a cycle of toxic behavior that creates a deep barrier between him and his family.

Mike is a typical suburban father with financial means. He lies to his community to handle a sudden crisis involving his family, avoiding police contact.

Helen is Amelia and Toby's mother. She works with her husband to comply with extreme demands to secure their family's safety.

Toby is Amelia's twelve-year-old brother. His schedule and routines make him a subject of intense surveillance.

Stuart is Kylie's friend who possesses a strong interest in escape artistry, a skill set that proves surprisingly relevant.

Tammy is Marty's girlfriend who abruptly vacates his life, leading to the end of their relationship.

Colin is a bank manager who is friendly with Rachel and Marty. He handles emergency loan paperwork when Rachel makes a desperate plea for financial assistance.

Anna is Erik's daughter. She lives in a psychiatric facility as she attempts to recover from a severe traumatic event.

Cheryl is Tom's wife and stepmother to his children. She struggles with substance use and relies heavily on therapy to manage her profound personal grief.