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. When a local murder seems too quickly solved, Indigo is inspired to do some investigating of her own. The thread she finds leads to something much bigger than she could have imagined. The victim was not innocent and his past ties connect to a web Indigo quickly gets tangled in. Meanwhile, she 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's up against before time runs out and the wrong man is put on trial.