In 1947 Whitbourne, Newfoundland, Alan Hepditch, a by-the-books but squeamish and somewhat dimwitted criminologist is constantly being tormented by his fellow ranger candidates and his sergeant, Bill O'Mara. Before Hepditch can quit, O'Mara, as a sort of punishment, assigns him to his first posting at Swyer's Harbour, where five sheep mutilations have taken place over the past year. When he arrives in Swyer's Harbour, Hepditch has a more serious crime to investigate, that of the murder of a local, mentally slow woman named Tryphenia Maud Pottle, better known to the locals as Young Triffie.

En 1947 à Terre-Neuve, un malheureux garde forestier est envoyé dans le petit port isolé de Swyer’s Harbour pour enquêter sur une simple histoire de mutilation de mouton. Il se retrouve alors confronté de très près à un meurtre odieux qui le dépasse totalement.