Her personal history led her to London and Charlie was determined to meet her half-sister. Samy, of course, accompanies him on his journey. On the way to visiting Sherlock Holmes' house, they meet Tracy, a young psychotic girl, who begs them to help her: her sister's ghost would have come to warn her that she was in great danger. Will they be able to prevent Tracy from suffering the same tragic fate as her dead sister a few years ago?