Irene Adler is an opera singer to whom Sherlock Holmes refers as "The Woman." She's featured in I think the first SH story, "A Scandal in Bohemia." If you don't have time to read it, watch the episode from the series with Jeremy Brett.
Ooo the dying detectives is one of my FAVES! I felt so sorry for holmes tho! ;_; "A sick man is but a child.." I kinda felt sorry for Watson too, with the way Holmes treated him there.