Set in London, a city shrouded in mist and fog at the end of the 19th century, a musical based on the Sherlock Holmes. People's daily lives are threatened by a serial killer, Jack the Ripper, but Holmes deduced that a criminal organisation is involved. The murder was masterminded by Moriarty, a genius mathematician, at the request of a government official. Meanwhile, Holmes is reunited with opera singer Irene, an unforgettable woman who outwitted Holmes once before.