Tom is a charismatic headteacher whose mysterious nature leads various characters to project their fears and fantasies onto him, influencing the community around him.

Nicola is Tom's wife and Freddie's mother, initially perceived as mild-mannered but revealed to be more complex as the story unfolds.

Rebecca is Joey’s sister-in-law, known for her reserved demeanor and complicated past, which affects her familial connections.

Freddie is the teenage son of Tom and Nicola, whose perspective and growth are essential for understanding the complexities of identity within the story.

Jenna is a student at Tom's school, who navigates her complicated home life and friendships while dealing with suspicions about Tom.

Jack is Joey's older brother and a heart surgeon, who provides insights into character dynamics as Joey and Alfie live with him and his wife.

Alfie is Joey's husband, characterized by his previously idealized image in Joey’s eyes and their shared history at an Ibizan resort.

Frances is Jenna's mother, whose mental health condition leads her to distrust Tom and influences the story's unfolding.