The Man with the Twisted Lip

Holmes discovers Dr. Watson in the black shadows of a smoke-filled opium den in the basement of the very house where Holmes is investigating his latest murder case! But of course the good doctor is only there to hunt down the drug-addicted husband of his wife's dear, but distraught, friend. Sound confusing? For all but The Great Detective, it probably is. And we haven't even talked about the murder yet!