On the university campus, a murder suddenly occurred, leaving the police with many mysteries. When they were at a loss, a college student came into their sight. From the identity of a criminal suspect to the right-hand man of the police, this change made Mu Su feel that the case a few years ago might have a turn for the better.
His girlfriend disappeared, and all the vows he made were ruined. In order to get his girlfriend back, he decided to stay at a university in the city. He will soon graduate. After nearly seven years of waiting, the truth will finally come to light. The long sleepless nights of hope will finally be rewarded. The unknown truth behind all this will also be revealed to the public one by one at the pace of Mu Su.