As the small village of Lochdubh has no dentist, locals travel 20 miles to Frederick Gilchrist's dental surgery in the town of Braikie. Although Lochdubh's one-man police force, Hamish Macbeth, prefers the more modern, painless procedures practiced by dentists in the city of Inverness, a blinding toothache one morning convinces him to give Gilchrist a try. Upon arriving, Hamish finds the dentist dead on the floor, a victim of nicotine poisoning. Discovering that the deceased was a non-smoker, Hamish must put his own toothache on ice -- to extract a murderer on the loose.