Something is amiss at a remote castle isolated in the Scottish Highlands. Raving recluse Ranald Guthrie, much despised laird of Erchany, has been wandering his halls obsessively reciting an old Scottish poem: Timor mortis conturbat me. Fear of death disturbs me. In the depths of a howling winter night, Guthrie falls to his death from the tower of his castle. Inspector Appleby is called in to investigate this deadly accident. Immersing himself in the lonesome world in which Guthrie spent his final days, Appleby must separate dreadful truth from chilling legend to determine what really happened on that terrible night.