Queen of the Gods by Katharine Corr, Elizabeth Corr

After defying Hades, Deina must choose: become a goddess, or fight for her humanity. The epic mythological fantasy that started with Daughter of the Underworld reaches its heart-pounding conclusion. Betrayed, Deina is now bound to the Underworld—and Hades wants her to stay. Hades promises immortality, power, and even the chance to be with her friends forever, including Theron, for whom Deina’s heart aches. But Deina refuses. In giving up her humanity to become a goddess, she would be beholden to Hades, and her friends would become mere playthings—dead playthings. After defying the wrathful deity, Deina needs an ingenious plan and plenty of allies if she’s going to escape her fate. The answer may lie in a storied artifact—a powerful torc made by Hephaestus himself, which was broken into pieces and hidden by Tyche, the goddess of luck. Unfortunately, monstrous Aristaeus is searching for the torc as well, with visions of harnessing its power to turn the Theodesmioi into his unstoppable army. Deina and her friends must stop him at any cost—and the cost may be high, indeed. Thrilling clashes, sumptuous settings, and heartrending sacrifices are woven throughout this unforgettable tale of mortals and gods, love and ambition.