The Emperor's Lady-in-Waiting Is Wanted as a Bride (Manga) Volume 4 by Kanata Satsuki

Lyse has finally uncovered the root cause of the mysterious trouble around the palace and the capital—the only problem now is that she’s caught in the middle of it! Against an opponent who would stop at nothing to achieve their goals, can Lyse win on her strength alone? She just might be about to learn that two hearts are better than one.

Beyond that, Lyse fears for what comes next. Defeat means the worst for Olwen and the emperor, but victory still means bidding farewell to Sidis as he and the imperial retinue return to Razanate. And after everything that’s happened, Lyse isn’t quite ready to let go yet...