Watch Power Rangers Alien Rangers

The young Rangers try to help their friends, the Aliens, as they lie at the bottom of a dried up swimming pool. The kids bring all of the water they can find. Rita shows up at the Command Center basement and tells Rito and Goldar not to activate the explosives until they have gotten the Zeo Crystal. Rito accidentally activates it, leaving he and Goldar to sweat it out, hoping that they will get the Crystal before they are blown to bits. With the help from the kids, the Aliens are able to rehydrate enough to defeat the Hydro Hog with the Shogun Megazord. The wise person of the village, Ashalla, reveals to Aisha that she has her Zeo Crystal but implores her to stay and help the animals. Aisha decides to stay and sends Tanya with the Zeo Crystal back to the Rangers who bid a teary farewell to Aisha on the Viewing Globe. They welcome Tanya into the Power Ranger family. Billy activates the Zeo Crystal Transformer and the world is returned to the present. The Rangers say good-bye to the Alien Rangers as they return to Aquitar. Rito and Goldar barge into the Command Center and confiscate the Zeo Crystal. The Rangers return as the explosives begin to go off. Billy throws himself on the control panel and receives an electric current through his body. Alpha teleports the Rangers and Tanya out as the Command Center falls down around them. Outside, they look on in shock as the Command Center is destroyed, not knowing whether Alpha and Zordon have survived.

Aisha arrives in Africa to search for her peice of the Zeo Crystal, while Rito and Goldar finally reach their destination of the Command Center, after days of attempts, only to accidently trigger the explosives' deadly countdown. Also, the Aquitians face the arriving Hydro Hog.

Tommy lands in the distant past in an American Native tribe and Katherine lands in the Australian outback both in search of their Zeo Crystals. Zedd and Rita decide to attempt to bring the Alien Rangers' greatest enemy, the Hydro Hog, to Earth to suck up all the water, thus destroying them. Katherine is faced with a moral dilemma between helping an old woman or getting her Zeo Crystal. Tommy is challenged by True of Heart, a wise shaman, to listen to his heart and find his crystal. Katherine decides to help the old woman, who rewards her with her crystal. Tommy is successful in finding his crystal while Zordon and Alpha are able to block for the time being Zedd's delivery of the Hydro Hog to Earth.

Adam finds himself in the Orient, searching for his Zeo Crystal. He looks for the wise Kai Ogi for advice. Rita and Zedd send the evil Arachnafiend to destroy the Alien Rangers. Billy seeks advice from Professor Kinder for help with the Phase Modulator that will power up the Zeo Crystal once it is assembled. The Alien Rangers visit a carwash to rehydrate. The Arachnafiend catches Billy in a web but he is later rescued by the Alien Rangers. Adam learns a lesson and Kai Ogi helps him find his Zeo Crystal. The Alien Rangers defeat the monster with the Battle Borgs and Shogun Megazord. Rito and Goldar continue to wander lost in the tunnels.

The young Rangers are sent through a time hole on their individual quests to find their pieces of the Zeo Crystal. Rocky lands in Mexico in the 1930s and a young boy named Pablo tells him that the crystal is inside a volatile volcano. Zedd calls on Witchblade to prevent Cestro, the Blue Alien Ranger, from finding a pure water source. The Aliens and Billy take a trip to the Angel Grove Aquarium to ask the fish where the purest water is. Cestro fights Witchblade at the stream. Rocky valiantly climbs the volcano and retrieves his crystal, saving the village from the volcano's eruption. Rocky discovers that he has traveled back in time and that Pablo is actually his grandfather. The Aliens defeat Witchblade with the Shogun Megazord.

The young Rangers and Billy take a well-needed break at the local water slide park. Meanwhile, Goldar and Rito are sent to the tunnel under the Command Center to find out the secret entrance and blow it up. Rita and Zedd look for the most mischievous kid in the water park to recruit for their dastardly scheme. They discover that it is Bulk and turn him into the Brat Boy monster. Rito destroys the map that was supposed to lead him to the entrance, leaving Rito and Goldar hopelessly lost. The Alien Rangers return from Aquitar just in time to rescue the kids from Brat Boy. Zedd and Rita make Brat Boy grow and he fights the Battle Borgs. The kids appeal to the human side of the monster and are able to reach Bulk inside and calm him down. Bulk emerges from the monster and turns on Rita and Zedd. Zordon summons the Rangers and informs them that they must recover the pieces of the Zeo Crystal and reassemble it in order to recover their powers.

Billy works on a device to purify Angel Grove Lake so the Aliens can hydrate. Zedd and Rita send Erik and Merrick, the Barbaric Brothers, to toxify the water. Rito places a force field around the Aliens, trapping them in the toxic water. Later, the kids are able to trick Rito and they break the force field, freeing the Aliens. Zedd and Rita unleash the Barbaric Brothers on the city. The Aliens use the Battle Borgs and the Shogun Megazord to defeat the monsters. The Aliens return to Aquitar to rehydrate.

Billy works on a device to turn the world back to normal. Rito and Goldar decide to get the Power Coins from the vulnerable young Rangers, but the kids outsmart the monsters. Billy finishes the device and asks the others to meet him so they can change back. Goldar and Rito follow them, steal the Power Coins and are joined by Rita and Zedd. The young Rangers witness the destruction of the Power Coins, but not before Billy is able to use the machine on himself, restoring him back to his rightful age. The Alien Rangers are dehydrated and teleport to a local fountain in the center of town. Rita and Zedd turn Billy's device into the Slotsky monster. The Aliens are called to help and use the Battle Borgs to defeat Slotsky. The Aliens are honored as heroes by the people of Angel Grove.

The Alien Rangers vow to help Zordon and the young Rangers despite the danger of being out of their watery environment. Alpha defuses the bomb, just before it goes off. Master Vile deploys his army of monsters, Professor Long Nose, See Monster, Garbage Mouth, Parrot Top and Crabbie Cabbie, who invade the city. The Aliens morph into the Alien Rangers and call their powerful Battle Borgs to fight the creatures. They call on the Shogun Megazord to finish the job. Master Vile is furious and returns to his planet in a huff. The Aliens promise to help defend the Earth until the others can figure out a way to the world of the future.

The young Rangers watch helplessly as Angel Grove is attacked by a huge Rita, Zedd, Rito and Goldar. Master Vile's evil plot to turn the world back in time has succeeded in leaving the Rangers as powerless as children. Only they realize that the world has turned back. Goldar and Rito plant a bomb outside of the Command Center. Master Vile assembles an army of monsters to destroy the Earth. Zordon decides he must solicit help from the Alien Rangers of Aquitar, a distant planet covered entirely by water. The Alien Rangers teleport across space to defend the Earth in its most dire hour.