Fia Riftborne thought joining the Sidhe Guard was the hardest choice she'd ever make.

She was wrong.

Taken prisoner by the very shadows she was sworn to fight, Fia uncovers a devastating truth. The wraiths who brought destruction to the Isle's western border aren't monsters at all, but a race of people from a dying realm called the Kálfar, and they believe Fia's growing powers are tied to their survival.

As war looms on two fronts, Fia must navigate a world of shadow magic and political upheaval. A disgraced Kálfar lord builds an army in the south while tensions within Sídhe reach a breaking point. And the Void that gave Fia her power is calling—but answering it means betraying everyone she left behind.

The Guard. Her friends. Laryk.

In a war where nothing is as it seems, choosing the wrong side could cost her everything, including the brooding commander whose darkness seems to recognize her own.