Mattie, an intelligent automaton skilled in the use of alchemy, finds herself caught in the middle of a conflict between gargoyles, the Mechanics, and the Alchemists. With the old order quickly giving way to the new, Mattie discovers powerful and dangerous secrets—secrets that can completely alter the balance of power in the city of Ayona. This doesn't sit well with Loharri, the Mechanic who created Mattie and still has the key to her heart—literally.