Dickens' final novel, The Mystery of ______ Drood (5)
I believe the answer is:
edwin
(Other definitions for edwin that I've seen before include "Sir - Landseer, artist" , "Dickens's Drood" , "Wined (anag.), man's name" , "Dickens novel 'The Mystery of . . . . . Drood'" , "Old king's" .)