Since killing a man in New Orleans Mercy's kept her head down. With diet, exercise, and work, she thinks she can keep wolves and memories at bay. She's wrong. The Costilla gang wants revenge and Mercy will pay with her life if they can get to her.
Her father, Tommy Watts, decides to send her to an isolated castle with an ominous past owned by a pair of innkeepers with no past at all. Tommy's solution is simple. He'll take care of the Costillas while Mercy's tucked away out of sight in the countryside. If only he hadn't sent her cousins with her, three girls with issues and a lot of duct tape. Dad said Mercy would be safe there, but she's the only one. The castle is hosting a baseball camp and the competition is about to get fierce and deadly.
After surviving a kidnapping and battling with spriggans, Matilda Whipplethorn finds her life in a suburban human house pretty boring. She's been excluded from school because of her fire-making abilities and her former friends are afraid of her. Salvation comes in the form of a life-threatening illness. Her tutor, Miss Penrose, needs a medication and there's only one place to get it, the spriggans. Matilda heads back to the antique mall to save Miss Penrose even though it just might cost her everything.