1902: Fourteen-year-old Aida Briar Norton's life at school is interrupted when two men arrive, claiming they are to take her to her parents. Every instinct declares that they are lying, but Aida has no choice but to go with them when they produce a letter allegedly signed by her father. On the train, every word they say makes her more certain she is not safe. She takes matters into her own hands and escapes them. With her parents missing and kidnappers on her heels, what is a girl to do but disappear in London? Aida does everything she can to search for clues of her parents' whereabouts. She takes up disguise after disguise until she becomes a maid in 221 Baker Street. There Aida waits for the return of Sherlock Holmes. Where have her parents gone? What secrets have they been keeping from her? Does she want to know or will the truth shatter her world completely?