Scarred noblewoman Lenora drowns herself, awakening Nerissa, a lake siren who heals her and ignites forbidden love. Together they uncover a monstrous truth: Lenora's husband Cedric is her half-brother, the arsonist who destroyed her family. As they plot revenge, Nerissa's magic fades—only a pure human heart can save her. In the end, love demands the ultimate sacrifice.
