An immortal teenager vows to stop a powerful witch whose rampage threatens the world in this conclusion to a fantasy/romance trilogy.Zera Y'shennria's heart is no longer in the possession of the witch Varia d'Malvane. Now Varia's witch brother and Zera's love, Prince Lucien, has it. He offers to return her heart, but Zera declines since her immortality as a Heartless is an asset. She, Lucien, and their friends will need their strength to face Varia, who may now be the most potent witch in the world. She has the power of the Bone Tree, which Zera, as Varia's Heartless, helped her find. Though Varia no longer has her heart, Zera connects with her via dreams-seeing through the witch's eyes as the hate-filled figure kills and destroys. Ending Varia's frenzy, which entails controlling the valkerax (gargantuan "wyrms"), involves the Glass Tree, which, like the Bone Tree, is a source of magic for witches. While some believe the solution is splitting each of the two Trees, which have a shared history, Zera has an entirely different plan with which others don't concur. She hopes to save as many lives as she can even if that means sacrificing her own. Wolf's rousing tale is rife with dilemmas. The Trees, for example, consume witches. While some characters suggest merely waiting for the Bone Tree to finish eating Varia (despite myriad deaths in the interim), the Glass Tree may very well do the same to Lucien. Meanwhile, Zera remains encumbered with guilt over her part in Varia's locating the Bone Tree. But notwithstanding Zera's past transgressions, she's strongly sympathetic in this final installment. Her first-person descriptions of her "unheart"-somehow capable of skipping a beat or melting at Lucien's romantic gestures-are frequently endearing and indicative of the author's sublime prose.An exhilarating and endlessly charming series finale with a striking hero and a sinister witch. (acknowledgements, author bio)