The Game is on

You recently have discovered that you are a descendant of Sherlock Holmes. You received a letter in the mail stating that you must immediately come to London as your great relative has left something for you in his flat. Upon arrival you become locked inside. You find another letter that was left behind for you by Mr Holmes explaining that this is an escape test that he himself has constructed for you. One final puzzle with a sensational twist. You will have to use your powers of observation, deductive reasoning and critical thinking to prove yourself clever enough to escape the flat. Are you up for the Challenge?