A terrific film that, along with Train to Busan the following year, shows how far Korean horror has developed since The Host. Starting slowly, the story develops its characters and the sense of post-war suspicion well. Subtle clues, and some less subtle, gradually add to the sense of unease as the father earns the villagers' trust and friendship before they turn against him. The last third builds mercilessly towards its tragic conclusion. Despite nods to the Piper of Hamelin and The Fog, the film never feels derivative and the viewer is pulled along with the dripfeed of revelations. Well worth a watch.