Grace, a destitute countess, is on the brink of marrying the esteemed Duke Ansel, who claims to have fallen in love instantly. However, her world shatters when she overhears Ansel's disheartening words about their impending union being merely a charade. It becomes clear that Grace is being used as bait to expose a lurking enemy targeting the duke. Despite her dismay, she resolves to play her part, accepting the duke's offerings and devising a scheme to ensnare the perpetrator.