A 16-year-old American student and rugby star at Sherringford Academy, who seeks a connection to his family's history with the Holmes family and befriends Charlotte.

James's father, who attempts to reconcile with his son and supports him and Charlotte during their time at Sherringford Academy.

The middle-aged detective assigned to investigate the mysterious events at Sherringford Academy, though he is often exasperated by the teen detectives' involvement.

Charlotte’s older brother, who runs an international security service and is protective of his younger sister, often intervening in her affairs.

A highly intelligent tutor of the Holmes family who encounters professional and personal challenges connected to Charlotte and his family’s legacy.

August’s brother, implicated in a drug bust and seeking revenge, as he navigates the complexities of his relationship with Charlotte.

August’s former fiancée, who harbors resentment against Charlotte and plots against her under the guise of a nurse.

A student at Sherringford Academy interested in manipulating drug use for personal gain, who becomes entwined in the novel’s darker plot elements.

A freshman at Sherringford Academy who has a crush on James, becoming unintentionally involved in the unfolding drama.

Charlotte’s carefree and wealthy roommate who participates in school activities and assists Charlotte in her schemes.

James’s roommate at Sherringford Academy, whose feelings of inadequacy and temptation lead him to make dubious decisions.

James’s creative writing teacher at Sherringford Academy, interested in crafting a sensational story about the academy’s events.