Marple: The Moving Finger (2006)

When troubled war veteran Jerry Burton and his sister Joanna relocate to the quiet little village of Lymstock in order to allow Jerry to recuperate from injuries received in what he claims is a motorcycle accident, they are expecting nothing more than country sleepiness and tedium. Much to their surprise, however, they find themselves embroiled in the middle of scandal and secrets; someone is sending vicious poison-pen letters to the residents. A local dignitary has already taken his own life over the letters, and it's not long before local gossip Mona Symmington also commits suicide after receiving a letter. But when the letter-writer apparently resorts to murder, Jerry finds his curiosity stoked despite himself, and he's not the only one; Miss Jane Marple is also in Lymstock, and she's decided that it's long past time someone got to the bottom of this unpleasant business.