We were supposed to separate... but the cold duke refuses to let me go!

Summary

I was reborn inside the world of a novelNot as the heroine, but as a background character even less important than a "backup plan"the greedy, man-crazy villainess: Grace.According to the story, Grace is supposed to toy with the cold Duke Zane and then abandon him, setting the stage for his destined meeting with the true heroine.But if she doesn't follow the plot, the story will spiral toward a devastating war, and Grace will die as a result!To save herself, Grace decides to stick to her role as the villainess, even if it goes against her true nature.The problem? She was originally a serious and kind-hearted girl, making her utterly terrible at playing the part of a proper villain.And the result?Instead of getting heartbroken and moving on as he's meant to, Duke Zane falls madly in love with her, insisting on staying by her side:"I'll never let you go Don't expect a goodbye from me."Can Grace rewrite her fateOr will this unexpected love turn the entire story upside down?