The Eternity Gate by Katherine Briggs

Book1 of The Threshold Duology

Summary:

Destroy the key. Save her people and herself.

The Eternity Gate is found, and kings and monsters battle over its legends of treasure. But rumors whisper that someone stole the gate's ancient key.

Seyo, handmaiden to the princess, keeps three secrets. First, she's gifted in fire, not light, and may as well be cursed. Second, she translates a prophecy warning that the gate does not offer treasure but judgment. Third, Jorai, the scorned prince and Seyo's confidant, entrusts her with the key and disappears.

Surrounded by war, Seyo and her companions embark on a journey to seek help from a faraway empire and find Jorai, unaware of the trap awaiting them. But what should Seyo do with the key? Who can survive judgment, especially someone as flawed as her? Will hiding the key—or destroying it—save her people or ensure their defeat?

Opening Lines:

Through the paper window, lingering stars winked against a cold sky, the morning of my eighteenth winter passed and I, Seyo, came of age.