Fury Convergence. Senyaza Series, #6

Branwyn, a magical artificer, reluctantly teams up with both her estranged sister and a meddlesome monster to track down some stolen children. Soon she finds herself entangled in a ghost story that will lead her from the ruins of a small town to a road trip across Faerie--and into the darkness of her own heart. Meanwhile, the Wild Hunt, faced with the most dangerous haunt they've yet seen, struggles to save rather than destroy the tormented soul at its core.
But doing so may tear the Hunt apart, and the final decision between salvation and survival ends up in the most unlikely of hands.