In a society where one's identity is determined by genetics and psychological traits, Lin is a Shut who is obligated to dedicate her life to loving only one person. On the other hand, Dosung is a Destroy who continuously subdues his explosive and violent tendencies. Despite Dosung's harsh refusal of Lin's affections, their lives are endangered by a string of horrific murders, with authorities closing in on the case. In this contrasting world of concealed truths and undisclosed secrets, can Lin succeed in transforming Dosung's behavior before it's too late? Follow their exhilarating love story as time ticks away.