The moving finger

"Lymstock is a town with more than its share of shameful secrets - a town where even a sudden outbreak of anonymous hate-mail causes only a minor stir. But all that changes when one of the recipients, Mrs Symmington, commits suicide. Her final note said: 'I can't go on'. Only Miss Marple questions the coroner's verdict of suicide. Was this the work of a poison-pen? Or of a poisoner?"--Publisher description.