A small town high up in the north. Thick snowflakes fall on Newcastle, Christmas is just around the corner. However, Detective Ashworth's excitement quickly fades. On his way home, he sees an old lady sitting dead on the train, her body showing stab wounds. And no one has seen anything. Together with his boss Vera Stanhope, he sets off to Northumberland to the small town of Mardle, where the deceased lived. The investigations there present them with a puzzle. The old lady was pious and modest - who could have had an interest in her death? When a second body is found, the clues also lead to the small guesthouse "Harbour Street." And its guests remain stubbornly silent.