Holmes has just successfully solved a new case by retrieving a priceless set of jewels that had been stolen. Unfortunately, the jewels' owner reveals that the necklace Holmes returned to him is a pale imitation... and everything seems to incriminate the detective!
A true descent into hell starts for Sherlock Holmes. London begins to have doubts and starts to lose its trust in Holmes who is incapable of refuting suspicions or of disproving the charges against him. Even Doctor Watson's unshakable faith in his friend starts to waver as the famous detective avoids Scotland Yard and increases strange behaviour: night escapades, blackmail, destruction of evidence... can Holmes go so far as to murder someone?