The Mighty Morphin Power Rangers have been turned into children by Master Vile, and Earth is now at the mercy of his monster hoards. In desperation, Zordon communicates with the distant planet of Aquitar, an ocean planet that is home to a humanoid race of water-dwellers called Aquitians. Five of the Aquitians also protect their planet as Power Rangers, and Zordon requests their help in protecting Earth. Together, the Mighty Morphin Alien Rangers are able to defeat the monster hordes and send Master Vile running back to the M51 Galaxy. However, Lord Zedd and Rita Repulsa still intend to finish what he started by conquering Earth.