Bullied and desperate to escape her coastal town, nineteen-year-old Claire finds a dying stranger chained to the salt flats. Armed with only a bucket, she fights to keep him alive—unaware she’s saving Poseidon, the fallen god of the sea. As their bond becomes love, Claire discovers the mermaid blood her mother concealed and a power that could restore his ruined kingdom. But ruthless hunters, a hostile royal court, and the woman Poseidon once betrayed want to tear them apart. To save the god who stole her heart, Claire must claim her place beneath the waves—or lose both worlds to an ancient darkness.
