Marilyn is a 21 year old spy at the top of her game. She's young, well-trained and focused at all times but during a failed mission she encounters the likes of Xiumin, the 23 year old protege to the criminal who wants her dead. At first Xiumim is just a weird boy with a stalker like crush but eventually he starts winning over Marilyn with his charm and his determination to protect her at all costs even if it means death for him. Can Marilyn and Xiumin love defy all odds? Or are they just another couple of star crossed lover?