In 1777, one year since he had taken reign, King Jeong Jo bears a perilous palace life with his dedicated court servant, Gap Soo, amidst opposition and threats from those around with political ambitions. Meanwhile, Eul Soo, a member of a secret assassin group, receives orders to kill Jeong Jo. Gap Soo, who had also been in the same secret assassin ring as Eul Soo, later confesses to Jeong Jo about his dark past and his motive for coming into the palace. To Gap Soo’s surprise, Jeong Jo asks Gap Soo when he had given up being an assassin, then orders him to just leave the palace. However, Gap Soo finds out that there is another assassin besides him and frantically returns to the court, only to discover Eul Soo in combat with Jeong Jo.