The story is 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 30-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.

By accident, the 12-year-old Preston is given a blank check and when he fills in $1,000,000 - he is able to get it! He is having fun spending the money, but the gangsters who owned it want it back...