Many years ago, queen of Atlantis Atlanna was saved by a lighthouse keeper Thomas Curry. The two fell in love with each other and gave a birth to their son, until Atlanna were forced to return to her kingdom. Now, Arthur is grown up man, who uses his Atlantean heritage to help people on seas, having not idea about his mother role. But his life changes after he finds out that he is the heir to the Atlantean throne. As Arthur's half-brother, Orm Marius, openly let Arthur take the throne, Arthur now struggles with his love for the upperworld and his kingdom. Meanwhile, David Hyde, a pirate who father died by Arthur's hand, now seeks a revenge.
