A benevolent but misguided female scientist and her assistant capture Swamp Thing to learn how his DNA works. Anton Arcane turns more of his henchmen into mutants to retrieve Swamp Thing and experiment on him himself.

Dr. Arcane desecrates an Indian burial ground in search of Lost Cavern, home of the fabled Fountain of Youth. Arcane unearths a tablet covered with ancient pictographs and forces Tomahawk to decode the writings. Thus begins a race to see who will find the Fountain of Youth first - and who will leave it unscathed.

A nuclear-powered satellite crashes into the swamp. Swamp Thing teams up with Bayou Jack and Tomahawk to help NASA recovery the satellite before its radioactivity can permanently harm the ecology of the area - but Dr. Arcane beats them to it and seizes the nuclear power plant for his own evil uses!

Dr. Arcane travels to the Amazonian Rainforest in search of "the trees that never die" and enslaves a local Indian tribe to harvest their sap, causing extensive damage to the ecosystem. Swamp Thing liberates the Indians and uses the sap to restore the rainforest.

Believing that Swamp Thing can grant him immortality, Anton Arcane turns three swamp thugs into human-animal hybrids, the Un-Men, and sends them to capture him. Instead, they capture two lost boys, so Swamp Thing and friends intervene.