Victorian London filled with the hiss of steam engines. Smog-filled skies filled with airships and streets filled with horseless cabs. London, where girls from high society disappear and die, and the only clue is a mechanical scarab. This mystery can only be solved by Mina Holmes, the niece of the famous detective, who actively practices her uncle’s deductive method, and Avaline Stoker, a vampire hunter, the sister of the aspiring writer Bram Stoker. Who is behind these crimes? Under the leadership of Irene Adler, the girls will have to enter the secret service of the Crown and find themselves in the most dangerous adventure of their lives.