While Abby and Liz track down the secret Conclave facility, Jason Woodrue conducts experiments on Swamp Thing and makes an incredible discovery.

While Swamp Thing senses a growing darkness within the swamp, Abby’s return dredges up her dark history with the Sunderlands. We learn more about the mysterious Dan Cassidy.

Something unnatural is happening in the swamps outside Marais, Louisiana. When a mysterious illness strikes the town, CDC investigator (and former Marais native) Abby Arcane is sent to investigate.