Brutal and manipulative take on events - including an extended rape - which lead up to a bloody revenge killing from controversial French director Noe.
Cinematic depiction of rape is possibly one of the most difficult things to balance the moment when authenticity ends and events become gratuitous.
This French shocker has already caused a furore by virtue of the nine-minute rape scene which acts as a catalyst for a mindless revenge slaying later on.
Noe employs the now familiar trick of running the narrative backwards, so at the start we see two of the victim's friends wreaking no holds-barred vengeance.
Of course, at this stage, we don't know about the earlier sex assault - all we see is two men barging into S&M gay club Rectum in search of a man called La Tenia.
Avengers Pierre (Dupontel) and Marcus (Cassel) eventually track down their quarry and a fight erupts with one poor sap's head stove in (at length) with a fire extinguisher.
The movie then backtracks into the evening to show the two friends hunting the alleged assailant down and the actual gorefest itself in a dimly lit subway.
Rewind even further and the audience gets an insight into the victim Alex (Bellucci) and her two friends - Marcus, her current boyfriend, and Pierre, a former lover.
We learn that, contrary to what we already believe, they are not a couple of out-of-control thugs but ordinary, middle class jack-the-lads out for a good time.
The effect is one of sheer manipulation; at the start you could not imagine their motivation - but after witnessing what drives them disgust is replaced by empathy.
However, few will be able to stomach the bestial assault in the murky nightclub or the rape, the length of which tips the scene into pornographic violence.
Director Noe philosophises in that Gallic way that the story "describes the ancestral link between a wound and vengeance."
But it could be argued he goes rather to far to get his theory across - and his point is lost in the inevitable row over what is permissible on screen.