A grisly discovery fished out of the River Thames marks the start of an intriguing new case for private detectives Grand & Batchelor. September, 1873. Private enquiry agents Matthew Grand and James Batchelor have been hired by timber merchant Selwyn Byng following the disappearance of his heiress wife. The only clue they have to go on is a badly spelled note demanding the princely sum of 5,000 if Byng is ever to see Emilia again...