A special assignment reaches master detective Sherlock Holmes, who has actually retired to his retirement home in Sussex to breed bees. However, he cannot refuse the request of His Majesty, King Edward: the renowned investigator is to bring a diamond safely from South Africa to the United Kingdom. Before Sherlock and his friend Dr. Watson can take on the honorable task, however, the valuable gem is stolen. This happens despite numerous security precautions, which even included several duplicates. Holmes starts his investigation and soon has a large number of suspects, including those from the highest circles...