I Married the Crown Prince's Enemy

Mariana, feared for her command of Mo clan mechanisms, is raised deep within the palace so that her loyalty to the throne can be secured. She expects a marriage to Crown Prince Sebastian once he opens the mechanical wild goose lock she brings to court. In a previous life she quietly showed him the solution, and afterward watched the Mo clan get buried alive when he took the throne. Reborn on the day the imperial decree arrives, she holds her tongue and learns that Sebastian has picked someone else, so this time she sets out to change her destiny by wedding his fiercest rival.