It is at least a trifle ridiculous that online forums argue about character development between this French film and the 2008 American remake, The Strangers. Neither film relies on character development, not even in part. The closest we get to understanding the protagonist victims is through the repetition of poor decisions that leave them subject to further torture.
The film here remains superior to the glossier English version. The opening sequence could itself function as a taut if unmotivated horror short with no explanation and no qualms about being that way. In fact, it bears only minor connection to the tortured stars of the rest of the film, a simple intro to the savagery to come. This is certainly where both films are on par and is thematically, the source of any and all horror.
The unmotivated and casual terror employed by the strangers demands an explanation and remains unnerving in its absence. We can explain very easily the vampire and werewolf and countless other monsters, supernatural or not. We can explain serial killers and demented minds whose stories develop their abnormality as the point of fear. And, of course, we can explain the ingenious ability of the human mind to perpetuate
