London, 1919. As the planet celebrates the signing of the Treaty of Versailles, Sherlock Holmes and his faithful friend Dr. Watson are confronted with a macabre and chilling discovery. On the banks of the Thames, a human limb is found, the hand of a soldier who is said to have lost his life two years ago in France, in the trenches of World War I. However, the severed limb appears to have been cut recently. How is it possible that it was found in London two years later? Sherlock Holmes and Dr. Watson are pressured by government officials to abandon their investigation and come under the target of a dangerous, horrific creature with supernatural powers. Holmes and his friend begin to believe that something very dark and dangerous lies behind this mysterious case.