Captain Planet is held hostage by Nukem, Blight and MAL.

Nukem's radioactive presence at a leaking nuclear power plant triggers a meltdown.

Nukem decimates the ozone layer so he can feast on ultra-violet rays.

The teens cross paths with Cold Warrior Commander Clash, but their true opponent is Captain Pollution, a creation of Blight's.

Commander Clash joins the Planeteers to stop the eco-villains and Captain Pollution.

The Planeteers are saved from crashing by a solar beam, created by Dr. Pollo. He and his daughter live on an island, creating new and innovative ways to use solar power. Kwame falls in love with his daughter, while also becoming suspicious of their lab assistant, who turns out to be Leadsuit, sidekick to Duke Nukem. Nukem's plan is to turn their solar convertor box into a nuclear device, so he can feed on the nuclear energy generated by the beam that saved the Planeteers earlier. The Planeteers and Captain Planet stop Nukem in his tracks, but shocks from the nuclear energy erases Dr. Pollo's memory, prompting him to set out to rediscover his inventions.

As key World leaders come together under one roof to discuss how to best prevent the growing spread of pollution and o-zone damage worldwide, Zarm returns to earth with a plot to snuff out the Planeteers. Calling a meeting of all the eco-warriors greatest foes, Zarm is able to tap into earth's energies and drain the earth itself of all it's resources. Only Gaia stands in his way, but Zarm has a final surprise to ensure she does not become a problem..

Zarm, having disabled Gaia and re-taken his position as spirit of the earth, begins turning the world into little more than a dead husk. With Gaia reduced to an old woman with not much longer to live, the Planeteers and Captain Planet face their greatest threat yet...

Sly Sludge and Duke Nukem dump toxic waste in the Amazon rain forest, imperiling Ma-Ti's village. Ma-Ti returns to the village with Planeteers and find it in flames. When they fail to stop the fire, Ma-Ti hunts the culprits alone.