The story is actually set in 1947, following a long-retired Holmes living in a Sussex village with his housekeeper and rising detective son. But then he finds himself haunted by an unsolved 50-year old case. Holmes memory isn't what it used to be, so he only remembers fragments of the case: a confrontation with an angry husband, a secret bond with his beautiful but unstable wife.
Laura Linney....Mrs. Munro
Hattie Morahan....Ann Kelmot
Patrick Kennedy....Thomas Kelmot
Hiroyuki Sanada....Tamiki Umezaki
Roger Allam....Dr. Barrie
Colin Starkey....Dr. John Watson
Philip Davis....Inspector Gilbert
Nicholas Rowe....Matinee 'Sherlock'
Frances de la Tour....Madame Schirmer
Madeleine Worrall....The Haunted Woman
Sarah Crowden....Mrs. Hudson
Zak Shukor....Matsuda Umezaki
Filmography links and data courtesy of The Internet Movie Database.