With seventeen prince hearts in her possession, Lira is one of the most revered sirens in the sea. But a slip-up prompts her mother, the Sea Queen, to transform Lira into what she most loathes—a human. Lira has until the winter solstice to deliver Prince Elian’s heart to the Sea Queen or remain a human forever. Although he is heir to the largest kingdom on Earth, Prince Elian calls the ocean his only home. Hunting sirens is more than a hobby—it’s his life. When he rescues a drowning woman, she promises to help him find the key to exterminating all sirens, but can he trust her?