London, 1898.
Holmes has just solved a recent 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 as the culprit!

Thus begins Sherlock Holmes' downward spiral. London begins to have doubts and lose its trust in Holmes, who is incapable of refuting suspicions or disproving the charges against him. Even Doctor Watson's unshakable faith in his friend starts to waver when the famous detective begins to avoid Scotland Yard and displays increasingly strange behavior: night escapades, blackmail, destruction of evidence... Could Holmes go so far as to murder someone?
Scrutinized by Scotland Yard, doubted by his stalwart companion Dr. John Watson, and behaving more erratically than ever, Sherlock Holmes is in what might be his darkest hour yet. His recent triumph in the case of a missing set of priceless jewels has turned to disaster; the necklace's owner accuses Holmes of returning a forgery to him, and there seems to be no evidence at the ready to clear his name. Has Sherlock Holmes become a criminal? If he is indeed a thief, what else is he capable of? As the questions and suspicions mount, will salvation be found or will there be nothing to stop the famous detective's seeming descent into darkness...
Dark and sinister, The Testament of Sherlock Holmes features a Sherlock Holmes like never seen before. It is a breath-taking story that will constantly surprise players through its twists and turns, especially those already captivated by Sherlock Holmes' dark side.
You are Sherlock Holmes, and this is your investigation.
Live a thrilling adventure and foil an incredible conspiracy!