Haute tension/ High Tension (Alexandre Aja, 2003)

For most of the film, High Tension (Alexandre Aja, 2003) seems like an ultra-violent, painfully graphic, Hollywood Horror film, with a plot that is somewhat more interesting. The end of the film, though, changes the viewers perception of the film entirely. With an almost Shyamalanian ending, High Tension turns itself upside down in the last 15 minutes, with a truly shocking use of the infamous unreliable narrator (as suggested by the camera Marie is speaking to while in her cell in the institution), which may suggest the concept of a subjective reality, or simply justify an hour and a half of torturous violence.
One of the more underlying, yet fascinating, themes of this film is that of gender. As previously alluded, this is not quite the average genre flick. High Tension is a film that is very much aware of the conventions of the genre, and the expectations of the audience. This movie makes some drastic departures from the genre as far as gender is concerned but, aware of these conventions, does not do so immediately.
The big reveal at the end, that Marie is actually one and the same with the killer, is really what brings the questions of gender roles to the forefront. The genre does not, in general, make room for female killers. This is High Tension's way of having a deranged female killer work within a well defined construct. The expected situation is that a demented, disgusting man, will hunt down and attack the pretty girl, most notably citing Halloween (Carpenter, 1978). Perhaps because of her guilt, Marie is projecting herself onto a generic serial killer, who she, and we, feel is a more appropriate killer.
The guilt that drives her to insanity, or vice-versa, may not stem strictly from the murdering of Alex's entire family. Her sexuality is alluded to a few times throughout the film. The first notable instance is as she is smoking a cigarette outside on the swing, she watches Alex through her window. There is a clear homosexual tone to this film, which is highlighted by this scene. The other big sexual tie is the parallel between her masturbation, and the killer's. While certainly the nature of the later is far more disturbing, this could be how she thinks of herself in these actions, since he only exists in her world.