From bestselling author Kelsey Impicciche comes the epic sequel to Voice of the Ocean. Heart of the Moon finds Celeste navigating treacherous waters on a quest to save her sister—and both the siren and human worlds—from the power hungry king of pirates.

“You didn’t honestly expect to walk out of here alive, did you?”

The worlds of sirens and humans alike have been devastated by the Pirate King, Leonidas. Human coastlines lie underwater. The siren kingdom of Staria has been abandoned. And Celeste’s beloved sister, Sephone, has been captured. But Sephone is no ordinary siren. Within her lies the Voice of the Ocean, an ancient power to control the sea itself. But now Celeste’s only chance to save her sister means trusting the handsome pirate who betrayed her, the son of the wicked pirate king himself, Captain Raiden Sharp.

Though Raiden vows to help, Celeste cannot forget the part he played in her sister’s capture. Nor can she ignore how her heart is still drawn to him. As Celeste navigates dangerous seas, siren politics, and ancient magics, she and her friends find themselves joining the crew of their enemy, who has reasons to hate Leonidas just as much as Celeste does.

Their epic quest takes them to exotic cities, on land and deep beneath the sea, and through the mysterious icy waters of the north. But Leonidas is always two steps ahead. He knows far more, commands almost every pirate ship on the ocean, and the Voice of the Ocean is only the beginning. If Celeste does not succeed soon, not only will he become more powerful than any human who has ever lived, he will become unstoppable.