Returning from a foreign holiday, Hamish Macbeth is worried because he senses a dark cloud of evil hanging over the Highland village of Lochdubh.
He learns that a newcomer, Catriona Beldame, is regarded as a witch and various men have been seen visiting her. Hamish himself is charmed by her until he finds out she has been supplying dangerous potions.
At first the villagers won't listen to him, saying that the loveless Hamish has turned against all women. He threatens to kill her so that when she is found murdered, he must clear his name and then work to solve yet another murder to bring peace and quiet back to his beloved village.
His investigations are complicated by a romance with a female forensic expert. Perhaps he'll get married at last!