The Wailing (2016)

This movie starts out intriguing and thought-provoking, and doesn't let up until the very end. In fact, the series of details supporting multiple theories will leave you pondering The Wailing for days. If you do a search online you'll find people with countless interpretations, which all seem perfectly plausible given the supporting details. Some movies just leave the story open-ended as a lazy way of encouraging thought and discussion, this one is anything but lazy. The Wailing is a quality horror approached from multiple angles. You have the outbreak of a disease which transforms people into highly aggressive killers. You have a Japanese stranger whom nobody trusts (given Japan's egregious history with South Korea). You have satanic shrines devoted to all of the diseased and dead villagers. You have an actual demon wandering around. You have powerful shaman's capable of remote attacks. Then you have the cops responsible for sorting everything out, who demonstrate the most frustratingly amateurish detective work you'll ever see. Overall, a deep movie that will have you pondering for days.