November 1902. The glamour and glitter of the London debutante season is torn apart by the reign of terror of a vicious serial killer. Renowned detective Sherlock Holmes and his friend and colleague Dr John Watson are reunited to solve a case which threatens to destroy the privileged tranquility of aristocratic society. Fog and shadows engulf the city, the body of a young woman is pulled from the River Thames. The police assume the victim is a prostitute, but Holmes swiftly establishes that she is, in fact, the beloved daughter of one of London's most aristocratic families. The killer uses the cover of thick fog to snatch the daughters of the establishment from their parents' homes. As the killer grows more confident, Holmes and his faithful assistant Dr Watson must use everything at their disposal to prevent more deaths. Despite being hampered by a wall of silence from the aristocracy and by the usual police blunders, the detective's extraordinary mind draws him ever closer to solving the case. But can even Holmes get to the truth about this complex and twisted killer in time to stop him striking again?