Mistakes have consequences. This one could unleash hell on Earth. As the most powerful undine healer since the woman who sank Atlantis, Calandra was supposed to be the saviour of her people. Instead, the malicious dragon spirit who haunted her dreams has been freed from the Abyss, the peaceful society of Sirenia has been plunged into revolutionary chaos, and her own brother, Zale, has inexplicably turned against her. Worse, though Calandra knows why she is going insane, she doesn't know how to stop it. When Calandra follows Zale on a rescue mission through the very gates of hell, she learns the disturbing truth about their people's past. With the threat of Madness growing ever stronger, can Calandra and Zale find a way to overcome their differences and undo a mistake that has plagued the undines for millennia . . . before the entire world pays the price? The Sphinx's Heart is the second book in the mind-blowing epic historical fantasy young adult series Rise of the Grigori. Continue the search for redemption with a cast of perfectly flawed characters on a hauntingly magical adventure that will leave you breathless. Mermaids, dragons, and angels like you've never seen them before. Buy today!