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. As the two investigators assess whether Byng has been telling them the whole truth, a second package brings an extremely unwelcome surprise.

At the same time, a human torso is found floating in the River Thames. Could there be a connection to Emilia Byng's disappearance . ?