You are Scotland Yard’s top investigators sent to Sherlock Holmes' apartment to investigate his disappearance! Sherlock has been kidnapped after probing into the theft of the 'Jewel of the Thames'. So, to recap the sequence of events: The Star of the Thames was stolen, Sherlock was investigating, got himself kidnapped, and now it is up to you to save him. Dr. Watson is unfortunately being trailed and cannot help you with this investigation, although he did mention something on his way out about your first clue resting on the mantel in Sherlock's library.
Once you enter Sherlock’s apartment, you'll realize that the door has been booby-trapped by Sherlock Holmes himself and now you need the key to get out. There are two things to complete in this room: first, you need to find a physical object inside the room that will negotiate Sherlock’s release from the kidnapper, and second, the actual key to get out!