Midnight and Silvered Glass. The Lorean Tales, #3

An expert assassin. A lonely fae princess. A mad scheme to save her life. Princess Betony craves a new purpose. After years honing her magical talents and forging bonds in Faerie, she returns home, a stranger in her own land. At the Winter Solstice Ball, she dances with a mysterious man, and for one magical moment, she doesn't feel so alone. Servant by day, assassin by night, Dorin is honor-bound to his clan, his chief, and the diplomat he serves.
Yet one dance and a searing kiss with the bewitching fae princess awaken a hunger for something beyond duty. All his chief's ambitions for a crown fade in light of his desire.  Though Betony is haunted by her masked gentleman, the quietly kind servant keeps capturing her attention. Dorin treasures their fleeting encounters, and when she suggests a more intimate meeting, he agrees. But while waiting for him, Betony overhears the ambassador's unsavory plan to kidnap her nephew, and Dorin risks everything to save her life, including an unwinnable war and his chance to claim her heart. Midnight and Silvered Glass is the exciting third standalone book in the Lorean Tales fantasy romance series.
If you like morally gray men, quick-witted women, and a dash of piracy, then you'll love Emily Michel's gender-flipped Cinderella retelling.