Deliverance by Erin O’Kane

The Fae love to make deals, never accept one unless you have no other choice.
There are some things in life worse than death.

Iris has lived a sheltered life in the village of Brine since birth, a settlement on the outskirts of the human lands. Fae stalk the forest that backs onto her land. To step into the forest means death. Everyone knows this and keeps away, living a mostly peaceful life.
That is, until one day when the fae come for Iris.
They need her to break the curse confining them to the darkness. Beautiful, seductive and their magic oh so powerful, Iris does not stand a chance. However, her knight in shining armour shows up in the form of another fae from a different court. He is of the Seelie and only wants to help her, keeping her from their enemies, the evil Unseelie.
After an attack she is unable to return home and must put her trust in her saviour.

Light versus Dark. Day versus night. Good versus evil.
The choice should be easy, but life does not work in absolutes.