If you don't know it, here's my take on the first two episodes. The scene is a French town set in impressive mountains (maybe in the Pyrenees, as there are wolves about). We learn that, years earlier, a schoolbus with forty children and two adults aboard went off a mountain road. The memorial to the dead is about to be unveiled when the story begins. Flashbacks reveal, in part, why the bus crashed. A little girl - Camille - returns home, despite having been killed in the accident. Cue extreme confusion, to say the least.
However, it's not just the crash victims who are coming back. It becomes clear that one of the revenants, an unspeaking little boy called Victor, was standing on the road and caused the bus to crash. An old man burns his house down with a revenant inside then takes his own life, jumping off a dam. A young man appears, searching for his girlfriend, only to find she had aged and is about to marry the local police captain.
It becomes clear that there's a related plot involving the huge reservoir nearby. The water level is dropping and the engineers can't think why. They keep this from the public, of course. At one point little Camille washes her hands in a church washroom and that old faithful horror movie trope, black water, gushes up the plughole. There are voices, too.
That scene is rather unusual, though. All in all The Returned has started well mostly because the conventional paraphernalia of the horror story is played down to near vanishing point. That leaves us with some excellent acting and beautiful visuals. The cast, as is usual with French TV and movie, is very easy on the eye as well as good at their jobs. And there is certainly horror, but not of the familiar sort.