Addie is an 11-year-old Scottish girl with autism who lives in the village of Juniper. She has a deep passion for sharks and a strong, uncompromising sense of justice. When she learns about the Scottish witch trials, she feels a profound kinship with the persecuted women and campaigns for a local memorial. She struggles with the sensory overload of her classroom and the prejudices of those around her.

Keedie is Addie's older sister and Nina's twin. As a university student who also has autism, she serves as a protective role model for Addie and encourages her to be proud of her identity. However, Keedie secretly masks her own neurodivergent traits at college in an exhausting attempt to blend in. This practice sends mixed signals to her younger sister.

Nina is Addie's older sister and Keedie's twin. Unlike her sisters, she is neurotypical and works as an online beauty influencer who posts videos about makeup and fashion. She often clashes with her family, feeling left out of the special bond her sisters share. She struggles with her own insecurities about her social status and career.

Audrey is a new student who recently moved to Juniper from London. Quiet but armed with a strong sense of fairness, she quickly takes an interest in Addie's passions and supports her memorial campaign. She actively seeks to understand Addie's autism and makes an effort to accommodate her sensory needs.

Ms. Murphy is a strict, cruel teacher at Addie's school. She shows no empathy for Addie's autism, publicly berating her for motor-skill difficulties and dismissing her academic questions. Her blatant ableism emboldens other students to bully Addie and creates a hostile classroom environment.

Emily is a student in Addie's class who frequently targets Addie with ableist bullying. She attempts to turn other students against Addie and uses cruel remarks to marginalize her. Underneath her hostility, she harbors insecurities regarding her reading difficulties.

Mr. Allison is the school librarian who provides Addie with a safe haven from the sensory overload of the hallways. He treats her with kindness and respect. He actively feeds her special interests by reserving books about sharks for her.

Jenna is Addie's former best friend. As they have grown older, Jenna prioritizes fitting in with the neurotypical social dynamics of the classroom. She ultimately distances herself from Addie in favor of spending time with Emily.

Mum is Addie, Keedie, and Nina's mother. She vociferously defends Addie's right to participate in traditional classroom environments and actively opposes Ms. Murphy's discriminatory suggestions. She attempts to mediate the conflicts that arise between her teenage daughters.

Dad is Addie, Keedie, and Nina's father. He works as a supermarket manager and often cooks for the family. He carefully prepares separate meals for Addie to accommodate her sensory aversions and provides a calm presence in the household.

Mr. Macintosh is the chairman of the local town council. He acts as a gatekeeper in Juniper, repeatedly dismissing Addie's proposal for a witch memorial. He fears the memorial will tarnish the town's reputation and deter tourism.

Miriam Jensen is a widow in Juniper who attends town council meetings and owns a tortoise named Ernest. She supports Addie's proposal for the memorial and displays her own signs of neurodivergence.

Bonnie is Keedie's childhood best friend, who also has autism. Because she lacked a proper support system, she was placed into a strict mental health facility. This traumatic event still haunts Keedie and frightens Addie.

Mr. Patterson is a tour guide who leads Addie's class on a field trip to the Water of Leith. His graphic and casually ableist storytelling about the persecution of historical witches deeply distresses Addie.