Scientist Alec Holland invents a growth substance that could end world hunger, but a plantation owner obsessed with immortality tries to steal it and causes an accident that turns Alec into a human-plant mutant, protector of the bayou.
While showing Delbert & J.T. around the swamp, Swamp Thing is captured and taken to New Orleans for government experiments. Delbert, J.T., and Bayou Jack plan to rescue him as does Arcane for his own plans.