Princess Lira is siren royalty and the most lethal of them all. Hearts are power, and with the hearts of seventeen princes in her collection, she is revered across the sea. When a twist of fate forces her to kill one of her own, the Sea Queen transforms Lira a human as punishment. Robbed of her song, Lira has until the winter solstice to deliver Prince Elian's heart to the Sea Queen or remain a human forever. Hunting sirens is Prince Elian's calling. When he rescues a drowning woman in the ocean, she promises to help him find the key to destroying all of sirenkind for good-- but can he trust her?