As the youngest daughter of the siren queen, Celeste's life is tightly controlled. Desperate to prove her worth and escape her destiny--trapped in the palace as a royal figurehead--she intends to join the Chorus, an elite group of siren warriors. With the final test on the horizon, Celeste feels the pressure to finally gain control over her temperamental Song--a magic gifted by the Goddess herself. But when Celeste encounters a seemingly harmless ship in Staria's waters, helmed by the intriguing Prince Raiden Sharp, her path veers toward forbidden waters.
Believing the handsome sailor to be innocent of any wrongdoing, Celeste defies siren law to save Raiden's life--despite knowing he is the son of a king who has murdered many of her kindred. The penalty for Celeste's betrayal should be death, but the queen offers her an alternative: right her wrong by assassinating the prince. Determined to first discover the truth behind the prince's clandestine mission, Celeste agrees to become human.
But the human world is nothing like she expected, nor is the prince the charming and noble man she assumed him to be. Disguised among Raiden's ragtag crew, she searches for the truth. But as Celeste finds her place aboard the ship, friendships--and attraction--begin to grow. Will Celeste be able to do what must be done? Or will her choices unravel a kingdom, devastating sirens and humans alike?