9 episodes about 'Killer Party, Yangsurimurder Case'. Detective Shin, a highly respected national police officer at the Yangsuri Police Station, finishes his chores and begins writing his memoirs. He travels back to past memories, starting from the mansion of Yangsuri theater director, 'Jeong Gwan-jang'. ... 'Jeong Gwan-jang' is preparing for an evening party while humming a tune. He invites the actors for his new play to his home. All the invited actors dress up according to their roles and gather at 'Jeong Gwan-jang's' mansion. The new play 'Jeong Gwan-jang' has written is about a murder case that occurs on a cruise ship, and he is ecstatic, considering it the masterpiece of his life. As the actors discuss the play and their roles one by one, the lights suddenly go out and screams are heard. 60 seconds later, when the lights turn on, 'Jeong Gwan-jang' is found collapsed with his face in a soup bowl. People think he is acting according to the play he wrote, but soon they realize he is unconscious. Who is the killer?