Nearly all the recurring players on the PBS show "Sherlock" are based on fictional folks found in Sir Arthur Conan Doyle’s original Holmes tales. The most obvious exception? Molly Hooper, the morgue registrar played by actress Louise Brealey. In fact, the show’s creators Steven Moffat and Mark Gatiss at first only intended the Holmes-assisting Hooper to appear in the show’s first episode. But over the years, Molly has become a genuinely beloved character as viewers tracked her unrequited crush on Benedict Cumberbatch’s titular sleuth and her predictably doomed romance with Andrew Scott’s villainous Moriarty.