Was it really Satan who occupied the locked attic room at 50 Berkeley Square? Was the resident of this townhouse his servant and a Jack-The-Ripper type killer who was living here in hiding? This book is not about the old ghost tales associated with this location because they are all fictional stories taken from published novels and magazine pieces of the day. It investigates the true and entire history of Berkeley Square from the May Day festivals of pagan times to demonic possession to succubus assaults to the exploits of a real Dorian Gray to a potential 19th century James Bond. Intense research also yields a final conclusion that is shocking. A genuine case where evidence proves the existence of a pact between Satan and human clients where souls are sold in exchange for power. It happened in 19th century Britain among some of the most powerful people of the day who are no longer remembered now. They may be now after this revelation.