Sherlock Holmes lives in retirement on the South Coast. He keeps bees, occasionally casts his fly fishing rod even plays his Stradivarius when the rheumatism allows. All too aware that he's older and slower, he's concerned that he might have lost touch, paranoid that he is an easy target for his enemies: there have been so many over the years. He never truly believed Moriarty - his arch nemesis - died at the Reichenbach Falls. So when Mary Watson (wife of his former associate Dr John Watson) tracks hi down to tell him she has seen her long-dead son, James, through the window of 221B Baker Street, apparently alive and well, Holmes is determined to solve the mystery and confront his own demons at the same time.