When Allura and Glenn defeated the ambitious King Asher and brought peace between the humans and merfolk, they thought nothing would ever stand in the way of their love again. Yet on the day of their wedding, the ceremony is interrupted by King Alanus of the sea, who declares that such a marriage is forbidden. Not willing to give up so easily, Allura and Glenn set out to meet with King Alanus to learn why he is so opposed to their wedding. Soon they learn of a great conflict between the realms of the sea, earth, and sky – a conflict that has thrown the land out of balance…