Sea So Blue (Water So Deep, #0)

Caspian is looking for his mother. Snatched from the beach as a child and raised as a half-breed Mer-Prince in the long-lost city of Atlantis, his turn to rule is coming fast. Caspian learns that the Mer in Oceania have found a method to visit land—a practice forbidden in Atlantis—and later return to the sea. Unfortunately, the “magic” method involves poison so potent that only half-breeds with undamaged lungs can survive it. When his Sea King father forces Caspian’s engagement to a mermaid...