When a killer mist emerges from the swamp and invades Houma, the Swamp Thing and Arcane must team up to try to stop it before it decimates the whole town. Meanwhile, Will and Abigail race to warn the town.

Will is taken hostage by two greedy explorers who force him to help them find the location of a mystic Mayan temple in the swamp, housing buried treasure and ghosts.

Will finds a car in the swamp, and attached are two married ghosts and their remains. The search for their killer, who just might be an old acquaintance of theirs, begins with the help of Will and the Swamp Thing.

When Arcane unleashes a genetic assassin into the swamp in the form of a virus, he gets more than he bargained for; he not only gets rid of the Swamp Thing, but he accidentally brings Alec Holland back.

Arcane's rival, Carla Jeffries (Tyne Daly) takes over his business, putting Arcane in the streets and stealing his "loyal assistant", Graham. The Swamp Thing discovers that she is a much more formidable enemy than Arcane ever was.

Graham leads a team of heavily armed mercenaries into the swamp to kill the Swamp Thing once and for all. Meanwhile, Tressa learns a few of the secrets of the swamp when she has a wounded visitor.

Arcane's experiment to bring out the inner beast in a human being works a little too well. He goes on a rampage and his assistants will suffer the cost as they, along with the Swamp Thing, search the swamp to stop him.

One of Arcane's mentors, Oliver Duncan, has died, taking his secret research with him. Arcane is determined to get at what is left of his research by seducing Oliver's daughter Louise, but she has plans of her own.

A film crew comes to the swamp for a TV movie about Arcane. Things quickly go awry when the lead actor is murdered and mysterious script pages appear detailing the truth about Alec's transformation and Arcane's crimes.