Hildur Rúnarsdottir is the only police detective in the isolated Westfjords of Iceland, desperately trying to forget her traumatic past by burying herself in her cases. Once Jakob Johanson, a Finnish police trainee with a knitting hobby, begins to work alongside Hildur to escape his own complicated life, it becomes clear that neither can keep their pasts away for long. But when a local man is found with his throat slit, underneath an avalanche that has buried much of the evidence, Hildur and Jakob must set their own problems aside and unravel the dark secrets and a killer that the picturesque fjords hide.