The Strange Relationship:
When it comes to big shock twists, this is one of cinema's greatest. (Don't read on if you're yet to watch the movie)
College friends Marie (Cécile de France) and Alex (Maïwenn Besco) are having a jolly old time heading to Alex's family home for the weekend. Until all the murdering starts.
It seems as if Marie is our hero, repeatedly saving Alex from a home-invading slasher, but all is not quite as it seems as we discover that Marie's all-encompassing love for her friend has driven her to psychotic meltdown; she is the woman on a murderous rampage. And all because she wants some alone time with Alex.
Could It Ever Work In Real-Life?
Unlikely - Marie's feelings for Alex seem to be very much unrequited, and we can't imagine Alex is feeling in the mood after watching her entire family die in gruesome manners.