Major crimes unit detective Seong-jin arrests Tae-sung for petty crimes, but shocked to find out that he is the notorious serial killer. However, Seong-jin becomes doubtful of his identity as the serial murder case is investigated.
Residents, who are evicted from their homes in a designated urban renewal, demonstrate against their removal. The police arrive and attempt to end the demonstration. Death happen that lead to the bigger problem.
Late 18th-century Joseon dynasty. The King is beleaguered and surrounded by traitors of the ruling elite. They plan to assassinate and replace him with a puppet. But the King has some aces up his sleeve that may help him defeat them all.
During fourth period, high schooler Da-jeong finds her classmate Tae-gyu dead in a classroom and Jeong-hun standing in front of him with blood on his clothes. In order to stop Jeong-hun from becoming the prime suspect, Da-jeong must help him find the real murderer, who is still inside the school building, under 40 minutes before period four ends.
