In a world plagued by demons and mistrust, Harriet Linby is on a gruelling journey north through Scotland to find her father. In this bleak world, humanity teeters on the brink of extinction, as the last humans are preyed upon by demons—known as the Possessed. In small survivor groups, humans live a nomadic existence, moving from place to place to hide from the demons, who roam the countryside in hunting packs. But Trust No One—for the Possessed are known to infiltrate survivor groups, spreading dissent and unrest. As Harriet travels north, she crosses paths with Will, a mysterious and secretive individual. Amidst the chaos and destruction, they forge an unlikely alliance, and together they set out into the unknown in search of Harriet's father.