When their mother disappears, Enola's brothers, Sherlock and Mycroft Holmes, decide to send her to a finishing school against her will. Instead, with the aid of her mother who had provided hidden funds and an elaborate cypher for her daughter to communicate with her, Enola runs away to London where she establishes a clandestine private detective career specializing in missing persons investigations. Furthermore, Enola must keep ahead of her brothers who are determined to capture and force her to conform to their expectations.