Summary/Synopsis: Ghost tells the story of the cyber investigation squad fights against the cyber crimes. Kim Woo-Hyun (So Ji-Sub) is the only son of a high ranking police officer. Woo-Hyun entered the police academy ranked first and graduated from the academy ranked first. As a detective, he then joins the cyber investigation department. Woo-Hyun then works to reveal the secrets of those that hide within the cyber world.