In the past, she had devoted her life to loving the third prince, only to have him cruelly break her heart by plunging a dagger into it. After years had passed, she was reborn as the fiancée of the fifth prince, who was regarded as foolish by the royal family. Upon meeting him, memories of her previous anguish resurfaced and she made a vow to safeguard this gentle, yet naïve prince. However, could he truly be as simple-minded as he appeared to be? Can she ensure his protection while also seeking retribution for the past? Will there be no concern from the royal family regarding this seemingly unintelligent prince and his companion's quest for revenge?