The Call of the Deep/Unsinkable/Five Thousand Fathoms Down/The Wrath of Kalmaar/Long Live the King

Nya has not yet found a way to regain her powers. But she gets help from the former master of water, her mother Maya. When the ninja also notice. that an unusual development of energy is taking place in the depths of the ocean, they set out to find the origin. What will they find? And will it help Nya get her elemental powers back?