Changmin is a genius. Despite only being a high school student , he is smart and by no means have an IQ like a kid, well his personality would gave it away though. His father, an Agent who works at the criminal unit division brought some work back home. An infamous case, dubbed as the 'Code Man' , simply because of their usage of computerised codes to commit crime. Changmin who accidently stumbled upon one of the evidence decide to decode one of them out of boredom. Low and behold he did it!