Grace Marchant has been many things: orphan, servant, and now beloved of Prince Bastien, heir to the throne of Larelwynn. But when a strange, ancient force threatens the very magic which brought them together, their happiness is put to the test. Innocent mageborn are being twisted into cruel, deadly nightborn, and only Grace and Bastien have enough power to stop them.

Striking a deal with the enemy should be unthinkable, but when the country of Valenti offers their aide, they cannot afford to turn their former foes away. But the partnership comes at a devastating price: Bastien must wed a Valenti princess. The only alternative is to find--and destroy--the source of the curse. But with time running out and her own magic turning against her, can Grace succeed both her kingdom and her heart are consumed by darkness for good?