When the fiancé of the sister of a Member of Parliament is found dead in mysterious circumstances, the man turns to Sherlock Holmes and John Watson to get an answer to the puzzle. Journeying to the small Wiltshire village of Barrow-upon-Kennet, Holmes and Watson are soon deep into a murder investigation. With few clues and a mounting death toll, Holmes and Watson realise that they are facing something much more sinister than a perplexed politician.