After one year of marriage, things could not look better for Jeong-hyun and Yun-hie. In order to celebrate the publishing of Jeong-hyuns manuscript, the couple decide to take a winter vacation along the East Sea. It turns out to be a trip neither will ever forget...if they survive. They meet a man calling himself M and agree to give him a lift. His expressionless face and penetrating eyes are disturbing enough but his rude actions and speech begin to interfere with the couples happiness during there trip, although they try to have a good time in spite of him. There contentment with this situation is short lived when they learn that M was in prison for a brutal crime. Meanwhile, the police have begun an investigation of a series of cruel murders along the highway...