Mira lives quietly in a remote community in Scotland - until one day she witnesses a stranger running for her life through the forest.

Shot and killed in front of her, the woman's body is quickly removed, the only clue to her death a crumpled piece of paper, and a spot of blood in the snow.

Mira discovers the paper contains a list of names, including her own, with another name she recognizes and the word 'watcher' alongside it.

Shocked, Mira suddenly begins to view her community with suspicion - and what she discovers throws her whole world into confusion...