Six months after the flooding of the valley much of the town's population have been evacuated, though some remain hoping to find loved ones taken by The Horde. An expert, Richard Berg, arrives tasked with finding the cause of the flood.
For months The Returned have been hiding in an area rendered inaccessible by the flooding. Julie, Victor, Camille and Claire have grown used to life as refugees amongst them but two of Camille's classmates are about to cause problems.
An uneasy Julie decides to leave the Domaine, Camille's growing relationship with Virgil upsets her mother, while Adele bonds with her new-born baby. Berg thinks that he may have found the reason for the flood.
Julie visits Victor's former home where an elderly neighbor tells her the reason for the massacre of his family. Berg and Jerome also decide to visit the hamlet where Victor's family were murdered and find his old drawings.
Jerome and Berg encounter Audrey, who has escaped from the Domain. Simon warns Adele to hide their baby from The Returned. Sensing Julie is in danger, Victor decides to leave the Domain - accompanied by Madame Costa.
Sandrine hands Audrey over to Pierre's men, who keep her in the cellar. Hiding in the church, Adele and Simon come to terms with each other. Julie has found Victor's father, who is now an old man in a coma and holds a dark secret.
In the Domain, Jerome is reunited with Claire, Camille and Lena but The Returned won't let them leave. The army lower the water level and plan to re-integrate the Domain with the rest of town, which would force The Returned into exile.
After the shooting the Seguret family try to leave town, but Camille cannot stay with her family and must join The Returned. Alcide takes Simon and Adele's baby to Lucy, but it is too late The Horde has dispersed.