Aimee is a 36-year-old successful actress working on films at Pinewood Studios in London. She is currently dealing with the sudden vanishing of her husband, emptied joint bank accounts, and missing passports. Diagnosed with transient global amnesia in her youth, she struggles with fragmented memories, which causes self-doubt as she faces an intense police investigation. In the alternate 1987 timeline, she is introduced as a five-year-old Irish girl named Ciara who is abducted and forced to adopt the name Aimee.

Ben is Aimee's husband, whose sudden disappearance prompts a police investigation. A former journalist, he was fired for gross misconduct two years prior. His relationship with Aimee is characterized by jealousy, isolation, and resentment over her acting success, as well as his firm refusal to have children with her.

A young woman who abducts young Ciara and takes her to a flat in Essex. She forcibly renames the child "Aimee," alters her birth date, and enforces strict rules. She uses a calculated mixture of psychological cruelty and sudden affection to control the young girl, effectively working to erase her original Irish identity.

Maggie's partner, who runs a betting shop in Essex and serves as a threatening adoptive father figure to the kidnapped child. Driven by greed and a desire for control, he creates a dangerous environment for the young girl. He introduces the child to firearms and normalizes a criminal lifestyle.

Aimee's charismatic costar on the set of their film, *Sometimes I Kill*. He is supportive and charming, offering Aimee a temporary safe harbor from her highly stressful personal life and the police investigation. He carries personal baggage from his past, including secrets related to his late first wife.

Aimee's (Ciara's) older brother in the 1987 timeline. He grows up in extreme poverty in Ireland under the rule of an abusive father. Traumatized by his environment, he blames his younger sister for their mother's death in childbirth and their dire living conditions, projecting his own pain onto her during their youth.

The lead police detective assigned to investigate the missing persons case of Aimee's husband. She is a persistent and observant investigator who quickly notices discrepancies in Aimee's story and the physical evidence at the house. She logically follows the mounting clues, applying steady external pressure on Aimee.

An actress who has maintained a bitter rivalry with Aimee since their school days. She actively tries to undermine Aimee's career by auditioning for the same prestigious film roles and intentionally adopting similar physical traits, such as dyeing her hair to match Aimee's style.

A relentless tabloid journalist who aggressively pursues sensational stories about Aimee's private life. She bypasses standard public relations channels to ambush her subjects, using extortion and unauthorized photographs to construct damaging narratives.

A police officer working alongside Detective Croft on the Ben Bailey case. He assists in searching the residence, securing evidence such as laptops and phones, and conducting routine inquiries.

Aimee's dedicated talent agent who manages her acting career and professional reputation. He works to secure high-profile meetings for her, such as a major role with the director Fincher, and attempts to shield her from negative press.