Third, and apparently final, book in the Rogue Mage series, this book seemed confusing to me. The dark powers under the Trine mountain have not been completely vanquished, and in some ways have grown even stronger. An emissary from the New Orleans mage enclave arrives, ostensibly to teach Thorn the things she must know to function in the diplomatic side of magery, but he turns out to be an assassin, working for her political rival within New Orleans.
The succubus Queen attacks early in the book, causing more murder and mayhem. The townspeople, aside from a few fundamentalist holdouts, have finally decided to trust Thorn, and ask her to put their old folks and children under the protection of the wards on her buildings, so the noncombatants are gotten out of the way for the coming big battle. They all believe they may only have days before the leader of the dark forces, known as the Dragon, brings all of his forces to bear on their town. He needs the blood of the Stanhope family to work the magic which will free him from his chains, as one of their ancestors, known as the Mole Man, used his blood to work the binding in the first place.
Thorn gathers all of her friends and allies around her, and they present a more or less united front when all hell breaks loose a couple of nights later. There are a couple of weird scenes when Thorn has an out of body experience and spends some time in the river of time, a higher plane where the seraphs, dark and light, do battle. She also gathers a hoard of objects of power that get used up, one by one and in occasional bunches, while battling succeedingly more powerful dark forces. In the end, she and her lost sister, Rose, must unite their minds as prophesied to conquer the Dragon.
The end felt rushed, and I think Hunter was already mentally and emotionally moving on to her Jane Yellowrock series, and just wanted to wrap up all the loose ends quickly. Thorn's development from a character with little power to one with major power happened far too quickly. If you're following this series, you've got to read the finish, but expect to be underwhelmed.