In England, 1888, fourteen-year-old Indigo Arabella Taylor dreams of becoming a detective, which as a young child is what she thought her solicitor father was. A local murder that seems too quickly solved inspires Indigo to do some investigating of her own. The thread she finds leads to a dangerous chain of events. Meanwhile, Indigo is befriended by a group of circus artists, specifically a boy named Atlas, who live a refreshingly different way of life than the stifling society in which she finds herself. Indigo must pick her allies wisely as she tries to unmask the secret society she finds herself up against before time runs out and the wrong man is put on trial.