In a small mountain community, two local people - teenager Camille, and Simon - who both died years earlier, suddenly re-appear at their homes. These ghostly characters appear in human form, they have not aged, and they are completely unaware of their own deaths. Camille and Simon assume they can rejoin the world of the living as though nothing has happened, but their return throws their friends and family into a state of turmoil. Camille's twin sister Lena is now three years older than her, and Simon's wife Adele is just about to get remarried, to Thomas, while Julie, a lonesome nurse, receives a visit from a very strange little boy. Seven years ago, the town was struck by a series of bloody murders, and now it seems they have started up again.

Simon approaches Adele, but Thomas finds out about his return. In the meantime, Camille is unable to fit back into her family again. Her mother Claire and father Jerome separated after her death, and now Claire is in a relationship with Pierre, an odd but charismatic figure who knew all along that the dead would return. Strange happenings seem to suggest that Camille and Simon may not be the only ones around to have been brought back...

Determined to come out of hiding and return to something resembling normal life, Camille invents a new identity for herself as cousin Alice. Her sister Lena finds a strange, fast-spreading scar on her own body. Simon gets closer to Adele; she finally accepts having him around again and opens up, announcing that they have a daughter, by the name of Chloe. Life around town is getting more and more disturbed; as for Julie, her old fears rear their ugly head once more but she is saved in the nick of time by Victor, the young boy she is sheltering.

Camille's new identity as Alice is going well, but Lena's scar is growing and seemingly draining her of energy. Lena is convinced that Camille is behind it and publicly denounces her to their friends. Julie can no longer keep Victor under wraps and the police take him away. She doesn't even put up a fight, wondering if he may have something to do with the death of her neighbour, Miss Payet. Adele gets back with Simon and introduces him to their daughter, Chloe but then discovers the true circumstances surrounding his death.

The dead gradually come out into the open but are unable to resume normal lives. Camille is rejected by Frederick, and Simon is abruptly separated from Adele and Chloe when Thomas shoots at him, in self-defense. Victor wanders around, looking for his murderer. Julie begins to have doubts: what if she was dead too? Lena is treated by the serial killer as he strives to keep his murderous impulses under control.

There's an electricity outage throughout the town. Pierre forms a community around Camille, who is now seen as a kind of prophet. After being killed by Thomas, Simon comes back to life again and takes off with the enigmatic Lucy. Julie finds refuge at Laure's house with Victor, whose body seems to be becoming strangely distorted. Lena grows closer to Serge but has to escape back to the town.