Flame and Crystal Thorns – Kay L. Moody
She vowed she’d never return to Faerie… But vows were made to be broken. As a human girl, Chloe is perfectly happy being back in the mortal realm where she belongs. She’s even become the town apothecary. When a fae from her past shows up begging her to return to Faerie, she utterly refuses. But then she finds out an angry group of mortals are using iron to hold an entire castle full of fae hostage. And of course, the hostages include Chloe’s older sister ...