A besotted mermaid surfaces to claim the object of her affection, with tragic results.It's 1914, 50 years since human witch Evie became a tentacled sea witch, anchored to an underwater lair by a powerful sea king. When Alia, a young mermaid princess, asks for Evie's help in winning the love of Niklas, young king of a small Danish kingdom, Evie agrees, taking Alia's voice as payment. However, Alia's twin sister, Runa, asks Evie to help her bring Alia back home: After all, the king is betrothed to another, and for all of Alia's allure, she doesn't stand a chance. Unfortunately, Runa's rescue attempt takes a dark turn, and the threat of war between human nations grows, as does the sea king's desire for revenge on those who threaten his people's existence. Runa just might be able to use her magic to throw a wrench into the war effort. Meanwhile Evie seeks to free herself from her prison and restore magic's balance. Henning never lets her oceancentric tale get too deep but keeps the stakes high and the focus more on friendship and sisterly devotion than romance, although Runa does bond with a handsome young human. Driven by Runa's and Evie's narratives, this story works as a stand-alone, but Sea Witch (2018) fans will be happy to learn Evie's fate. All characters are assumed white.An atmospheric twist on the classic Hans Christian Andersen tale. (Fantasy. 12-15)