In rural Brittany, a treacherous friendship develops between Sophie, the withdrawn and illiterate housekeeper for the wealthy Lilèvre family, and Jeanne, the embittered postmistress who bears a grudge against them. Simmering class tensions threaten to violently explode as the women’s growing antagonism towards the bourgeois Lelièvres’ privileged lives begin to turn into something far more malevolent, shocking and deadly.