Miss Moriarty, I presume?
(Book)

Brilliant private investigator Charlotte Holmes, who acts as an "oracle" on behalf of her fictional brother, Sherlock, has an appointment with a potential client, James Baxter, at her office at 18 Upper Baker Street. When Mr. Baxter appears, Charlotte recognizes him as her nemesis, Moriarty, whom she last saw at a disrupted ball at Moriarty's chateau outside Paris two months earlier. Moriarty doesn't explain his alias when he requests her assistance in extracting his grown daughter, Marguerite, from a cult based in Cornwall known as the Hermetists, and Charlotte wonders what he really wants. After consulting with the ever-attentive Lord Ash Ingram, Charlotte takes the case, and she and her friend Mrs. Watson head to Cornwall in search of answers. The more she learns about Marguerite, the more she wonders why Moriarty hired her. Meanwhile, the romance between Charlotte and Ash heats up.