The Moving Finger (1985)

Set during WWII, a brother (Andrew Bicknell) and sister (Sabrina Franklyn) arrive in a small country village only to receive a nasty poison pen letter insinuating that they aren't really brother and sister but, in fact, lovers. They discover these twisted letters have been received by many of the the townsfolk. Soon a suicide and then a murder follow and it's up to Miss Marple (Joan Hickson) to solve the case! Based on the novel by Agatha Christie and directed by Roy Boulting (THERE'S A GIRL IN MY SOUP). This filmed adaptation of the Christie novel introduces Miss Marple much earlier in the proceedings than in the book, but other than that this is a concise rendering of the novel and shouldn't disappoint Christie or Miss Marple fans. Personally, I don't think it's one of Christie's best novels (the solution is rather pedestrian) but as least they did it justice. Hickson, as usual, is impeccable as Marple. With Michael Culver, Hilary Mason, Richard Pearson and Deborah Appleby.