Smoky, peaty, high-proof - a crime pleasure from the Highlands. During his journey along the Scottish Whisky Trail, Commissioner Rohleff feels out of place from the very beginning. He should have resisted his eighty-one-year-old Uncle Gustav's persuasion to join this tour of the famous distilleries. The tour group is very experienced in handling authentic Scottish spirits, and everyone except Karl Rohleff is equipped with various flasks in their jacket pockets, wearing storm-proof clothing and exhibiting indestructible robustness. When one of the fellow travelers meets a fatal accident at the first distillery, Rohleff's professional instincts are awakened. Some aspects of this trip, especially the fellow travelers, strike him as highly peculiar. The whisky weaves a high-proof trail through the travel arrangement, gradually leading to a second death.