Li Jin is an ordinary office worker in Pingqi City. By chance, he gets the contact information of Cong Lin, a beautiful dance student, through a dating app. The two often have lively chats online, while each has their own life offline. One day, Li Jin suddenly learns in their chat that Cong Lin has died. But the person on the other end is actually Ai Yuhui, a junior high school student who only cares about playing games and bought the account on a secondhand marketplace. Sensing something suspicious, Li Jin takes a train to Changlin City and finds Ai Yuhui. This unlikely pair then sets off on a journey to uncover the truth. Was Cong Lin's death caused by her own inability to escape her circumstances, or was she murdered out of malice? What astonishing lengths will an overworked office drone and an internet-addicted teenager go to in pursuit of the truth?