Days after Holmes and Moriarty fall to their deaths at the Reichenbach Falls, London is in the grip of a fiendish new criminal mastermind.

The discovery of a brutally murdered body in a leafy suburb catches the attention of Pinkerton agent, Frederick Chase, freshly arrived from New York. Accompanied by inspector Athelney Jones, a devoted student of Holmes’s methods of investigation and deduction, Chase must forge a path through the darkest corners of the capital to shine a light on this shadowy figue, a man determined to engulf London in a tide of murder and menace.