Karen is a thirty-year-old part-time bookkeeper living a seemingly idyllic suburban life in upstate New York. Following a severe car accident in a dangerous part of town, she suffers from post-traumatic retrograde amnesia and cannot recall the events leading up to the crash. She relies heavily on her husband and attempts to piece together her missing hours while managing the stress of a police investigation.

Tom is a chartered accountant who has been married to Karen for two years. He is an idealist who trusts his wife completely and views their life as a comfortable, stable suburban dream. When Karen gets into a mysterious accident, he struggles to understand her actions while attempting to shield her from the ensuing police scrutiny.

Brigid is the Krupps' neighbor across the street and Karen's close friend. Having left her job as a manager to focus on fertility treatments, she spends much of her time at home, frequently observing the Krupps' house. She is highly attentive and deeply invested in the lives of her neighbors.

Rasbach is an experienced lead investigator assigned to a murder case in a rough neighborhood. He is meticulous and observant, quickly drawing connections between seemingly unrelated events. He approaches suspects with a mixture of professional skepticism and calculated pressure.

Jennings is a junior detective who works closely alongside Rasbach. He assists in questioning witnesses, analyzing phone records, and exploring alternative theories during police investigations.

Robert is a deceased man whose body is discovered in the same area where Karen crashes her car. He is found wearing a high-quality suit, suggesting he does not belong in the rundown neighborhood. His identity and reason for being in the area become the central mystery for the police.

Bob is Brigid's husband and the owner of a local chain of funeral homes. He works long hours and is frequently away from the house, creating emotional distance in his marriage as he withdraws from his wife's struggles with fertility.

Officer Fleming is a local police officer who responds to the initial traffic incident involving Karen. He handles the immediate aftermath of the crash, issues traffic citations, and performs preliminary questioning at the hospital.

Officer Kirton is a first responder who examines the accident scene. He questions why a woman from a wealthy suburb would be driving recklessly through a dangerous part of the city late at night.

Dr. Fulton is the physician treating Karen after her severe car crash. He monitors her recovery and diagnoses her with post-traumatic retrograde amnesia, advising her family on the healing process.

Dan is Tom's younger brother. He acts as a confidant and a source of familial support while Tom handles the stress of Karen's accident and the subsequent police scrutiny.

Jack Calvin is a defense attorney hired by the Krupps. He advises Karen on how to handle police questioning and manage the legal ramifications of her accident.

Duncan is a local teenager who discovers a crime scene. Rather than calling the police, he steals valuables from the body and pawns them, eventually drawing the attention of investigators.

Stacy is a counselor at a battered women's shelter who previously provided guidance and support to a woman fleeing a difficult marriage. She shares background information relevant to the legal case.

Susan Grimes is the District Attorney responsible for deciding whether there is sufficient evidence to bring criminal charges in the murder investigation. She evaluates the strength of the police's case against potential suspects.