Rite by Catherine Miller

Emmaryn was to wed that day. To choose a man selected specifically for her, the arrangement a blessing to all of her kind. She had only wanted a moment in the Grove, to remember her parents and settle her anxious heart. She was not supposed to leave the safety of the Spiral on her own. And yet… she did. Someone was waiting. With intentions contrary to all of their ways.
Elrik had tired of being alone. He’d forsaken his people, scarred and betrayed, with all their talk of sacrifice. He wanted something for himself. Someone. And he would have her. It would be the worst thing he had ever done. And he would spend the rest of his life more than willing to atone.