Do-hyeong is a bank clerk like any other. One day, he finally picks up the courage to propose to his girlfriend Ju-yeong. With the rings in his pocket, he goes back home in a hurry, but she’s nowhere to be found. At her workplace, nobody knows where she may be. Worried, he reports her disappearance to the police. Yun-mi, the detective in charge of this case, is first very suspicious of Do-hyeong who acts as if he was hiding something that would help the investigation. Because of that, Do-hyeong thinks he cannot trust the police anymore and decides to look for Ju-yeong by himself. But the more clues he finds, the more he discovers about his girlfriend’s troubling past.