At first, it's just millions of mosquitoes swarming over Lochdubh. But then an even greater nuisance descends upon the Scottish village: Trixie Thomas. The loud, intrusive woman has bought a guesthouse here and intends to stay, much to the horror of Hamish Macbeth. While the village women soon look up to Trixie with admiration, the men take to the barricades. Trixie wants to ban smoking and alcohol from Lochdubh, causing quite a stir. When Trixie is eventually poisoned, Hamish is also spitting venom and bile. He must investigate - in a village full of suspects.