The world of Aquitar was under the protection of the 5 Alien Rangers, and an unprecedented peace lasted for years after the destruction of the Alien Rangers arch-nemesis, Hydro Hog. But a new evil soon threatened the aquatic planet, Hydro-Hog's son the Aquavore. With his army of monsters, Aquavore began a powerful and brutal assault that the Alien Rangers couldn't handle. With the aid of Billy Cranston and Ninjor, new Rangers and new Zords were added to the roster of the Alien Rangers, and a new battle begins.