Following on from its controversial reception at Cannes, there were rumours circulating that Martyrs caused one or two members of the normally hardened audience attending the Film4 FrightFest in 2008 to exit the packed auditorium and throw up in the toilets. Regardless of whether the story is true or mere hype, it does reflect something of the visceral effect that Pascal Laugier's feature is likely to have on anyone who witnesses it. This is, after all, a film about a highly particularised, carefully manipulated act of extreme spectatorship - and it rather queasily implicates us all in its uncomfortable nexus of desire, guilt and abject horror.
Martyrs is also very much a film of two halves. As a traumatised and unstable Lucie (Mylène Jampanoï) blasts her way into a leafy home and shoots down the bourgeois nuclear family within, whom she believes responsible for abuse that she suffered 15 years earlier, it is left to her only friend Anna (Morjana Alaoui) to clean up the mess and to protect Lucie from the demonic creature (Isabelle Chasse) that dogs her every step. And so the first 45 minutes offer an arresting combination of ill-fitting but tautly interwoven genre elements - the hallucinatory home invasion of Switchblade Romance (2003), the shocking female vengeance of Baise-Moi (2000), the hideously contorted supernatural fury of Ju-On: The Grudge (2003).
Almost exactly at the film's halfway point, after viewers have been painstakingly pummelled and pounded into a vulnerable state of disorientation, unsure where exactly their sympathies should be directed or who has been the real victim amidst all the bloody carnage on display, events suddenly take a rather different dramatic turn, and a new kind of horror begins - and from here on in, Martyrs adopts the disarmingly reflexive strategy of calling into question what it is to 'witness' scenes of horrific human degradation, whether as a wide-eyed insider or a casual viewer.
Comparisons with Michael Haneke and his cake-eating critiques of the horror genre seem inevitable, but Laugier's preferred mode of audience interrogation is not a lecturing shout but an enquiring whisper, as he holds out the promise of a transcendent experience to be had from his abject materials, and then leaves viewers to supply it (if they can) for themselves.
The ensuing quasi-mystic reverie on sadism and suffering eludes the 'torture porn' label precisely by examining what those terms might mean, what appeal they might possibly have, and what questions - fundamental, even metaphysical questions - they might answer. The torments that Laugier shows in such repetitively banal detail are neither sexed up, nor ironised, nor sanitised, and will certainly not titillate or provoke any hipster laughter from the aisles - but they might just leave viewers as glaze-eyed and transfigured as the heroine in her final scenes, or alternatively as confounded and despairing as her own specific audience.
Martyrs, you see, turns out to be about the crowded auditorium of filmgoers that watches it, all filled with hope and dread for what is inevitably to come. No wonder, then, that it proves so confronting. Love it or loathe it, Laugier's shocker will get you thinking, talking and arguing with anyone else who has seen it - and survived to relate their experience.