Enola is a fourteen-year-old aristocrat who has been raised in isolation at Ferndell Hall. Uninterested in conforming to the strict gender norms of Victorian society, she prefers riding her bicycle and exploring the outdoors. When her mother goes missing, Enola relies on her keen observation and logical mind to uncover clues. Her journey forces her to develop her independence and face the harsh realities of the outside world.

Eudoria is the sixty-four-year-old widowed mother of Enola, Sherlock, and Mycroft. A strong-willed nonconformist, she rejects the restrictive expectations placed on Victorian women, preferring practical clothing and intellectual pursuits like painting and ciphers. Her sudden absence forces Enola to face the world alone and leaves behind a trail of subtle clues.

Mycroft is Enola's eldest brother and an official in the British government. In his late thirties or early forties, he focuses heavily on social standing and proprietary behavior. Having legally inherited the family estate, he assumes absolute authority over Enola's future, determined to send her to a finishing school to correct what he views as an improper upbringing.

Sherlock is a famous private detective in his early thirties. Known for his logical deduction and intense focus, he analyzes clues with a highly structured mind. Though he shares many of Mycroft's conventional views regarding women, he occasionally shows a grudging respect for Enola's quick thinking and perceptive questions.

Viscount Tewkesbury is the twelve-year-old son of an aristocratic family. Feeling stifled by his mother, who insists on dressing him in childish velvet suits and keeping his hair in long curls, he yearns for a life on the sea. His desire to escape his privileged but restrictive life closely mirrors Enola's own journey.

This individual is a dangerous figure involved in the kidnapping mystery of the young marquess. Operating in East London, they target wealthy families by presenting themselves as a spiritualist capable of finding missing persons. They utilize intimidation and complex schemes to exploit vulnerable people during crises.

Inspector Lestrade is a detective from Scotland Yard. He frequently relies on Sherlock Holmes for assistance in difficult cases. Professional and focused, he acts surprised when Enola offers him physical evidence and a strong theory regarding the missing marquess.

Mrs. Lane is the housekeeper at Ferndell Hall. She holds traditional Victorian views about propriety, often expressing disapproval of Enola's behavior and maintaining stereotypical views about outsiders.

The Duchess is the mother of the missing Viscount Tewkesbury. Distraught over her son's disappearance, she is highly overprotective and insists on keeping him in childish clothing, oblivious to his deep dissatisfaction with his sheltered life.

Mrs. Culhane is an older woman who owns a used-clothing store in East London. Pragmatic and aware of the dangers in her neighborhood, she provides a temporary refuge for those moving through the dangerous streets of the city.

Lane is the butler at Ferndell Hall. He is loyal to the family but easily embarrassed by unconventional situations, strictly adhering to the social decorum expected of an English estate servant.

Cooper is the lodge-keeper at the gates of Ferndell Hall. He monitors who enters and exits the grounds, providing Enola with her first clue about how her mother managed to leave unnoticed.

Dick is the son of Mrs. Lane, the housekeeper at Ferndell Hall. Enola decides not to entrust him with the critical task of sending her telegrams, preferring to handle the errands herself.