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?