Ella, a girl from the lower class, is forced to take the place of a missing wealthy heiress and get engaged to the fifth young master of a chaebol family to save her critically injured, comatose brother. Yet she accidentally steps into the domain of Theodore, the most dangerous, unhinged Second Master of the clan. Amid his oppressive aura and constant probes, she uncovers that behind this stand-in game lies a earth-shattering conspiracy powerful enough to topple the entire chaebol empire.
