As Kurt and Tristan battle for the Sea King's throne, sea witch Nieve kidnaps Layla and raises an army of mutant sea crature to overthrow the crown.

Galen, prince of the Syrena, is sent to land to find a girl he's heard can communicate with fish. He finds Emma and after several encounters, including a deadly one with a shark, Galen becomes convinced Emma holds the key to his kingdom.

In the future the world was a paradise--and then, in a moment, it ended. Duke Edmund Talbot has been assigned a simple mission: Go to the Southern Isles and make contact with the scattered mer-folk--those who, before the worldwide collapse of technology, had altered their bodies in the shape of mythical sea-dwelling creatures. Just a simple diplomatic mission that leads to intrigue.

Two years after the disappearance of their father, Sapphire and Conor, having moved with their mother to the town of St. Pirans, try to make a new life for themselves, but Sapphire, unlike her mother and brother, finds it increasingly difficult to adjust to her new circumstances and is drawn more and more to the undersea world of Ingo.

"Sometimes the death of your greatest dream is only the beginning... Princess Estelle has never been happy in her father's underwater empire, although she's ready to do her duty -- marry at fifteen and pass her three hundred years in service to family and empire. But when she's finally allowed to ascend to the surface and catches sight of a handsome human prince, a different -- and altogether dangerous -- dream starts to grow in her heart. Demetrius...