Cecilia, a fallen noble heiress, unexpectedly became pregnant in a black market conspiracy three months ago—only for a greedy, broke knight named Howard to pick up the token from that night and impersonate the man, tricking her into marriage. When Cecilia accidentally overhears Howard plotting to murder the fetus with poisonous herbs and seize her family estate, she decisively launches her counterattack.
At her wit's end, by a twist of fate she becomes the governess of Duke Frederick's—the empire's God of War—nephew. To give her child a sanctuary that even the king wouldn't dare search, and to help the duke fend off the royal family's marriage pressure, the two strike a "contract marriage."
Yet this duke, rumored to be cold-blooded and merciless on the battlefield, transforms into the ultimate "wife-protecting maniac" after the wedding. Under the duke's absolute protection and Cecilia's clever wit, they work hand in hand to send her ex-husband into the black iron mines, crush the greedy relatives scheming for her estate, and wipe out the underground black market that traffics in royal bloodlines.
Through countless life-and-death trials, Frederick not only discovers that Cecilia is the beloved from that night he has been desperately searching for over the past three months—he even draws his sword and declares war on the entire Senate and the Holy See to protect his wife and daughter. In the end, at the sacred cathedral baptism, the baby awakens the purest golden griffin bloodline, the conspirators are completely destroyed, the contract is voided, and the God of War duke kneels on one knee, ushering in their true grand wedding of the century.