Winning the international hacking competition, genius hacker Yeongcheon is a psychopath. Unable to work in a team, he is resigned, and in revenge hacks his boss Mr. Kim's personal life, using his son’s crime against him. Yeongcheon feels joy instead of guilt at Mr. Kim’s death, developing a murder addiction. Chasing after him, detectives Hyeonji and Jungyeong get involved in a plot twist.
