Under the Waves is a speculative fantasy series set in a near-future world where human–marine hybrids are persecuted by the surface government. The story follows Altair, a sheltered hybrid boy whose life is shattered when his mother is abducted during a government raid. He escapes into the ocean and is brought to Meliora’s Institute, a hidden refuge that shelters and trains hybrids to survive in an ongoing conflict between land and sea.