Arcane is possessed by evil spirits when he tries to practice voodoo.

The Swamp Thing is struggling to remain hopeful that he will be human again. Someone from the past comes to visit him, using Will to guide her to him. Only Will does not believe that she is who she says she is, and he is about to learn who he can and cannot trust.

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 has a secret from his past that comes back to haunt him. The swamp forces Will to face his inner demons, as well as the visitors that he does not know are waiting for him at the house.

Ann Fisk, a scientist and former student of Alec Holland, is in town. Ann's mentor, Carter LaRoche, has designs to build a recycling factory under Arcane's financing in the swamp. Ann must trust a strange voice in the swamp to expose an evil that she is not aware of.

Will falls in love with a lovely carnival worker named Amanda. Yet, Will becomes aware that Amanda is being held against her will by the shady carnie owner, Hurley, who has a dark agenda for Will.

Arcane is judged by the victims of his evil when he is killed by a laboratory accident. In this mock trial, he finds out who hates him and why, while he unsuccessfully tries to defend himself.

Ian James, an unscrupulous anthropologist, has come to the swamp to create a reputation for himself and the swamp suffers for it. Tressa is quite taken with him and in the process, the Swamp Thing is caught on film.

Nathan Stone is a heavy metal musician staying alone in the Kipp boarding house where the Swamp Thing terrorizes him with a series of mind games as he seeks to teach the shallow and egotistical rock star to take responsibility for his wicked lyrics that have led to the suicide of two teenage fans.

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.

Ann Fisk returns to the swamp to find the mysterious voice that guided her before on the suspicion that she knows who he is. The Swamp Thing has discovered a fascinating phenomenon about his power. Meanwhile, two brothers seek revenge on Arcane for his evil and Ann is caught in the middle.

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.

Dorian is an emotionally troubled teenager. He befriends Will, who begins to discover his troubled home life. Will and the Swamp Thing begin to try to help Dorian but there is one catch: Dorian could also be a vampire.

Still fruitlessly searching for her missing son Jim, Tressa is diverted when she hears the voice of her former boyfriend, a radio jockey from the 70's. Tressa begins a second hunt for answers, as she discovers what really happened when her boyfriend disappeared 18 years ago, guided by his voice from the grave.

Sheriff Andrews allows Dr. Arcane to hunt an employee for sport. To teach Andrews a lesson, the Swamp Thing traps the corrupt sheriff in a fantasy of the Wild West populated by familiar faces, forcing him to duel the evil Renegade Jake in a fight to the death.

The Swamp Thing's worst enemy is also the enemy of the swamp...himself.

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.

The ghosts of two temporally displaced Confederate Civil War soldiers appear in the swamp, one of whom is a previous resident of Will's house. The Swamp Thing assists Will to help the man to discover the mystery behind his wartime disappearance and make peace with his past.

Arcane finally resurrects his wife Tatania, only to learn the woman is an impostor. A few hours in the lab with this woman leads Arcane to discover the true whereabouts of his beloved wife and the identity of her captor; General Sunderland.

Arcane's genius mentor, Carl Mirador, has died. Using an experimental brain cell transfer, Arcane transfers all of Mirador's knowledge into his own brain. He also transfers Mirador's mental illnesses. Meanwhile, Will meets, and falls for, Mirador’s granddaughter, Dana.

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.

A hunter and his son search the swamp for an endangered hawk. Their relationship is in shreds, and their conflict may prove deadly for Will, who has been adopted by the swamp to help protect the hawk.

Arcane hosts a science conference, but it is crashed by a professional hit man who used to work for Sunderland and now has a score to settle. The Swamp Thing discovers the identity of the hit man and has a score to settle of his own.

A chemical plant causing toxic damage to the swamp is the key to a darker future. The owner of the chemical plant and an obsessed journalist are teleported to the future to see first hand what the damage is causing.