Olivia is a 35-year-old ghostwriter who specializes in writing memoirs for prominent women. She operates under her first husband's surname to distance herself from her estranged father, horror novelist Vincent Taylor. Currently facing massive financial debt after a public dispute with a rival author, she reluctantly accepts a contract to work on a memoir about the 1975 murders of her aunt and uncle.

Vincent is a highly successful horror author who has recently been diagnosed with Lewy body dementia, an illness that impairs his ability to write coherently. He lives in a sprawling California home under the strict watch of a caregiver. In 1975, he was the prime suspect in the unsolved murders of his siblings, a cold case he now wishes to document in a memoir.

Poppy is Vincent's younger sister who died during the 1975 tragedy at the Ojai carnival. As a teenager, she is an outspoken advocate for women's rights, lobbying for gender equity at school and clashing with her conservative mother. She uses a newly acquired Super 8 camera to document her family's daily life, capturing the growing tensions in her household.

Mr. Stewart is a young physical education teacher and track coach at the local high school in 1975. He lives next door to the Taylor family and maintains an unusually informal dynamic with his students. He regularly hosts bonfire parties at his house and acts as a mentor figure for several teenagers in the neighborhood.

Danny is Vincent's older brother who also died during the 1975 incident. He is known as a charming and popular survivalist with a deep love for the outdoors. Despite his outward popularity, he maintains a highly confrontational relationship with Vincent, frequently mocking him and instigating physical altercations.

Lydia is Olivia's mother and Vincent's high school girlfriend from 1975. During her teenage years, she is a dedicated track runner who relies heavily on her coach for support and guidance. As an adult, she lives an isolated life in Bakersfield, having left her family when Olivia was young.

Tom is Olivia's current romantic partner. He is highly sensitive to dishonesty due to his own complicated family background, making him particularly vulnerable to Olivia's fabrications. He believes Olivia's claims that she comes from a loving home and that both her parents are deceased.

Jack is Olivia's childhood best friend who now manages his family's vineyard. He serves as a vital voice of reason for Olivia, encouraging her to view her father with more empathy rather than relying strictly on her negative memories. He is married to Matt and maintains strong ties to Ojai.

Margot is Poppy's best friend in 1975. She is highly observant of the Taylor family dynamics and frequently encourages Poppy to participate in high school social events. Decades later, she provides Olivia with crucial context regarding Poppy's mental state in the days leading up to the murders.

Mark is Danny's best friend from 1975 and the father of Jack Randall. He provides Olivia with historical context regarding Danny's behavior and the tensions present on the day of the Ojai carnival. He maintains a firm belief that Vincent was responsible for the tragedy.

John is a highly influential author who successfully sued Olivia for damages after she criticized his decision to ghostwrite for a convicted criminal. He actively attempts to sabotage Olivia's new contract with Vincent Taylor by pitching himself as a replacement.

Nicole is Olivia's literary agent. She works diligently to revive Olivia's career following the John Calder scandal, initially unaware that her client is biologically related to the famous horror author they are negotiating with.

Alma is Vincent's live-in caregiver who manages his Lewy body dementia. She establishes strict boundaries to protect his health and intervenes whenever his interactions with Olivia become too stressful.

Patricia is the mother of Vincent, Danny, and Poppy. She is a conservative woman who frequently clashes with her children, imposing strict curfews that they routinely break. She relies heavily on substances to cope with the emptiness of her life.

Matt is Jack Randall's husband. He lives and works at the family vineyard, providing a welcoming environment for Olivia when she returns to her hometown to investigate her father's past.