Hildur Runarsdottir is the only police detective working on the isolated west coast of Iceland. She is desperate to forget her traumatic past by burying herself in her cases alongside her new trainee, Jakob Johanson. But Jakob's life has its own complications, and it soon becomes clear that neither can run from their pasts for long.

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 to expose a killer . . .