Jeong-hyun (Kim Ju-hyuk) celebrates the publication of his manuscript by taking his wife Yun-Hie (Choo Sang-mi) away for a vacation. At a stop, Yun-hie notices M (Park Joong-hoon) starring at her. As they both leave, Jeong-Hyun appears to accidentally reverse into M, and to defuse the situation, they accept his request of a lift. Increasingly unnerved by their passenger’s behaviour, they are relieved to reach the first destination of their trip and leave him behind them. After a night where a rock is thrown through their hotel bedroom, they leave only to have a dangerous encounter on the road with a 4×4. At the next town, the 4×4 again forces them to nearly have an accident. A furious Jeong-hyun gets out of the car to confront the driver who turns out to be M. This is just the start of a psychological game that will ultimately escalate to violence and murder.