큰 호수를 둘러싼 아름다운 마을 아치아라. 이웃끼리 서로 모르는 것도 없고 범죄 한 번 일어난 적도 없는 이 평화로운 마을의 사람들이 새로 부임한 교사 소윤의 존재에 신경을 곤두세운다. 부임한 첫 주, 소윤이 호숫가에서 우연히 백골의 시신을 발견하면서 마을의 평화는 하루아침에 깨지고, 절대 들켜서는 안 되는 마을 사람들 한 명 한 명의 비밀이 하나씩 밝혀진다.
Achiara is known as a quiet and peaceful village with hardly any crime. One day, Han So Yoon moves to the village to start her career as an English teacher. On her first day in the village, she accidentally finds a buried corpse. Her discovery shocks not only the town but also the villagers. And the villagers start to speculate on the identity of the dead person, and who and what made her get killed. The victim is known to be Kim Hye Jin who teaches painting in the town. And Yoon Ji Sook is suspected as the culprit. However, as the investigation led by So Yoon and the police develops, it turns out that more people could be involved and that the case is more complicated than how it looks. And the story grows more mysterious.