Episodes 01

“Pilot”

In a swamp outside of Marais, Louisiana, three men hired to drop cases of mutagen accelerator into Bayou Swamp are attacked by plants; with only one of them surviving. Days later, the survivor’s daughter, Susie, comes down with a mysterious illness that has been spreading throughout town. CDC doctor and former resident Abby Arcane, is sent to help. She reunites with childhood friend turned policeman, Matthew Cable, before meeting with Alec Holland, a disgraced scientist hired by businessman Avery Sunderland, to investigate further. The pair find the survivor’s body overrun with a plant creature, though Alec kills it. After meeting up with Abby’s reporter friend, Liz Tremayne, and being accosted by Maria Sunderland, the pair find the mutagen cases. While waiting for the results, Alec and Abby bond, revealing he had manipulated test results to prove himself right and she was responsible for killing Sunderland’s daughter, Shawna. After getting the results, Alec departs alone to find more of the cases, only to be violently killed and taken by the swamp. Abby rushes to find him, only to be scared off by a mossy creature.

Episodes 02

“Worlds Apart”

The police investigate Alec’s death, but disregard Abby’s claims. Maria meets with Madame Xanadu, who advises her against finding her daughter’s spirit and that she should put her regrets to rest. She refuses to however, later resting on Shawna’s bed next to her daughter’s corpse. Not long after biogeneticist Jason Woodrue and his wife, Caroline, arrive in Marais, the former meets with Avery, who berates him for the mutagen spreading disease instead of cultivating the swamp for land development like he wanted. Jason disagrees, claiming it is incapable of doing so, but Avery forces him to investigate the disease regardless. Susie dreams of a plant-like creature clawing at its body and feeling how scared it was. She later escapes the hospital and into the swamp, where she sees two men dumping more mutagen and killing an officer. One of the men, Munson, spots her and gives chase when she flees, only to be killed by the creature. Abby catches up to them while looking for Susie, who says the creature is Alec and he is confused as to what is happening.

Episodes 03

“He Speaks”

Munson’s body is resurrected by killer insects. Abby confides in Liz that the “Swamp Thing” is Alec. Abby later breaks into Alec’s lab and finds what he was working on. Munson attacks her, but she is saved by the Swamp Thing, who orders the insects to release Munson. Abby tries to reason with Alec, but when he says the disease is fighting to protect itself, she realizes that antibiotics make it stronger and uses immuno-suppressants to temporarily save the infected. Liz confronts loan officer Gordon about him secretly paying Avery, but he denies this. He later demands Avery return the payments or else he will talk. Matt’s mother, Lucilia, interviews Avery about Alec’s death; hinting at their past relationship. Shawna’s ghost confronts Maria about Avery’s infidelity. Avery attempts to procure funds from Maria’s inheritance, but she denies him. Meanwhile, Daniel Cassidy expresses his desire to leave Marais, learning from Xanadu that change is coming. Liz’s girlfriend discovers a piece of Alec’s boat. When Gordon threatens to expose the Conclave, Avery kills him.

Episodes 04

“Darkness on the Edge of Town”

A young man named Todd discovers a corpse hidden in a tree and unknowingly becomes infected. While working for Liz’s father’s, Delroy, Todd hallucinates and kills himself in the resulting panic, though not before scratching Delroy. Abby meets with Alec and obtains a sample of his tissue to study, with Jason’s assistance. Delroy begins to hallucinate a mysterious man and panics. While Lucilia, Liz, and Abby restrain him, Lucilia gets scratched. While Avery holds a celebration for the “plant flu’s” end, Maria attempts to get closer to the recovering Susie. Abby investigates the area where Todd was infected, finding the corpse and a hotel key. Liz looks up the hotel and learns of a similar incident in the past wherein the final victim vanished into the swamp. Abby theorizes they did this knowing they were infected. At the party, Lucilia sees a vision of Matt dying and attempts to shoot his “attacker” before Daniel disarms her. She scratches Abby, who rushes into the swamp. As she hallucinates a tall, faceless man trying to kidnap her, Alec arrives and cures her before returning the disease to the corpse before confirming Abby’s theory. Avery and Maria decide to take care of Susie instead of her uncle.

Episodes 05

“Drive All Night”

Swamp Thing meets a mysterious being, who tells him that the ghosts he has been seeing were events witnessed by past trees. Susie is possessed by Shawna’s ghost and lures Maria to the swamp. Abby follows Maria and tries to save her, but Maria nearly drowns Abby, who manages to swim away. Shawna’s ghost tries to drown Maria in turn, but Swamp Thing saves her. With Swamp Thing’s help, Abby discovers that Shawna was killed by an evil force that pulled her underwater. Avery threatens Liz to stop investigating Alec’s death, but she refuses. Daniel tries to leave Marais, but his arm bursts into blue flames at the border. Jason searches Alec’s lab and finds giant footprints that lead to a piece of vegetation. After analyzing it, he concludes that it has the same genetic material as Abby’s sample. Jason later tells Avery that a large creature is living in the swamp and that he needs it alive so he can study it. Avery obliges, offering the name of someone who can help him.

Episodes 06

“The Price You Pay”

Avery’s trackers try to capture Swamp Thing, but he defends himself against them. Lucilia sends Matt to investigate, who tracks down Swamp Thing in the process and fights him. Abby stops them, revealing to Matt that the creature is Alec. Matt confesses to Lucilia that he killed Alec on Avery’s behalf to protect her. Liz tells Abby that the thugs who attacked her and Daniel were sent by Avery. When Abby confronts Avery over Liz’s allegations, he hints at possible retribution. A comatose Daniel remembers the deal that he made with the Phantom Stranger that resulted in his being trapped in Marais. Jason manages to awaken Daniel, but his experiments on him almost transform the failed actor into a blue devil-like monster before Caroline sedates him. Xanadu visits Daniel and relieves his pain. Swamp Thing grows a hallucinogenic flower that makes Abby temporarily see him as Alec.

Episodes 07

“Brilliant Disguise”

Abby and Alec head to a rotted area of swamp. While she is collecting a sample, the darkness attacks and infects her with bacteria. Alec takes Abby back to his lab, where she is saved by the Green. Lucilia tells Avery that Alec is still alive and asks him to help her take Alec down before he comes for them. While searching the swamp, Avery betrays Lucilia and steals her shotgun. Just as Avery is about to shoot Lucilia, Matt surprises him and knocks him out. When Avery wakes up, he tells Matt that he is his father, and Matt gets angry at Lucilia for not telling him. While he is distracted, Avery stabs him. Lucilia shoots Avery in the leg, causing him to fall into the swamp. Alec tells Abby that his transformation is serving a higher purpose, and that she should move on with her life and not come back anymore. Abby goes to the CDC in Atlanta to try to find a cure for him before it is too late. An injured Avery emerges from the water and onto the shore.

Episodes 08

“Long Walk Home”

A wounded Avery wanders through the swamp. Losing blood, he begins to hallucinate. Swamp Thing finds him, brings him to the lab, and helps him recover. Abby is denied access to her sample results. Afterwards, she is confronted by the Conclave. Harlan is kidnapped after leaving Abby’s apartment. Avery returns the next day with Jason to “help” Swamp Thing, though he has also secretly brought Conclave mercenaries with him. Swamp Thing tries to make them leave, but the Conclave manage to capture him. Sensing that Swamp Thing is in danger, Abby heads back to Marais, but arrives too late.

Episodes 09

“The Anatomy Lesson”

At a secret Conclave facility, Jason conducts research on Swamp Thing, discovering that he can function without vital organs. As payback for trying to kill him, Avery bribes a judge to commit Maria to a mental institution. Upon further examination, Jason deduces that Swamp Thing is actually a humanoid plant that absorbed Holland’s memories after he died. Abby and Liz locate the facility. Daniel recovers and the Phantom Stranger shows him a vision of Liz and Abby being hunted and killed by Conclave security. Inspired, he decides to become the Blue Devil. Abby and Liz are able to free Swamp Thing while the Blue Devil takes out the guards, but Jason manages to escape. Returning home, he finds Caroline has overdosed. Swamp Thing returns to the swamp and retrieves a skeleton. A horrified Abby looks on as Swamp Thing confirms the body belongs to Alec.

Episodes 10

“Loose Ends”

Despite recovering Alec’s body, Abby tries to make Swamp Thing believe that Holland’s spirit resides within him. Nathan and his men attack, but Swamp Thing kills them, sparing only Nathan. Swamp Thing has one last conversation with Alec. Jason performs an experiment on himself to save his wife. Xanadu visits Maria in the mental institution and gives her closure, though at the cost of her sanity. Avery tries to reconcile with Lucilia, but when she refuses, he stabs her and dumps her car in the swamp with her in the trunk. After talking with Liz, Daniel is finally able to leave Marais. Swamp Thing and Abby decide to remain in Marais to combat the encroaching darkness together. Matt arrives at the station, only to find his fellow police officers dead. Jason, mutated by his experiment, attacks him.