The Dark is Descending by Chloe C. Penaranda

The thrilling finale to the Nytefall trilogy by New York Times, B&N and USA Today bestselling author Chloe C. Penaranda.Reeling from a shocking betrayal, Star Maiden Astraea must race against time to break the curse imprisoning her lover, Nyte. The only way to save him, may be to ally with a deadly threat.As daylight fades and devastation looms, Astraea and her companions embark on a quest to recover the Maiden's shattered key - the only weapon that can slay the gods threatening their mortal world.Dragons will rise, loyalties will be tested, and gods will clash. As the blood that binds them becomes a weapon to end them all, two star-crossed lovers must surrender to fate or make the ultimate sacrifice.