When the townspeople of Lochdubh begin receiving poison-pen letters, no one takes them very seriously, even if they are full of wild accusations. But Hamish fears that they might lead to something deadly. His instincts prove correct when the town's postmistress is found hanging from a rope with a poison-pen letter at her feet. Though it appears to be a suicide, Hamish suspects something more sinister. Attempting to trace the letters, the last thing Hamish needs is any distractions, but soon Jenny Ogilvie arrives in Lochdubh determined to seduce him. Realizing that she is unable to take Hamish's mind off his case, Jenny decides to do a little investigating of her own. Hamish finds himself in a race to solve the mystery of the poison-pen letters before someone else dies, including one likely target—Jenny.