THE ENDING (Sorry. There's no revenge.)
I think submachine's theory (on another thread) is an interpretation afforded by the filmmaker, but which, unfortunately, does not make sense.
From the original post:
"[Lying to Mademoiselle] is the one and only thing that Anna could do that would destroy Mademoiselle. Despite her pain throughout the ruined shell of her body, she retained enough strength and humanity in her mind to use the one and only chance she had. With a simple whisper she destroyed her captors, finally avenged her friend, and saved countless girls from falling into the same fate."
To me, this statement presumes too much about what Anna actually witnesses and the nature of her observation.
What the film tells us is that the point of inflicting extreme pain and degradation on a human being (not surprisingly, young females) is to induce transcendence in the victim. This transcendence we know Anna acquired because...well...she sees a squiggly fractal-like vision in the abyss. So if we accept this visual as indicating that there were indeed something beyond suffering, why necessarily does it have to be some beneficent "meaning"? And even if there were some "meaning" to it all, why then would Anna be disinclined to share it? Isn't that kind of 'heroism' not very transcendent at all, but really quite 'human' in its vindictiveness?
So there's a Catch-22 here. if Mademoiselle were correct that a female victim needed to be brutalized and completely destroyed in order to gain transcendent insight, then how at the same time could Anna have retained her own will and fortitude to defy Mademoiselle? This would mean she wasn't properly induced into transcendence, which would make her vision (and the fact that there is a beyond) untrue--which ALSO means she had nothing to lie about. In short, it's difficult to contend BOTH that Anna transcended her fate by defying Mademoiselle AND that Anna transcended base humanity to attain intimate knowledge of the divine.
Think about it another way: if there were some beneficent "meaning" behind human suffering, couldn't Anna have shared the truth of what she witnessed and THEREBY, in that way, end her suffering and that of all the hypothetical women who would follow as well? Doesn't it seem like the cult will only continue to torture more women now that Mademoiselle committed suicide--which is a clear indication that she DID discover SOMETHING?
Furthermore, what exactly are we to "keep doubting"? Are we supposed to keep doubting that a 'beyond' exists, or that it DOESN'T exist?
For me, the ending is intentionally ambiguous (and conveniently held from us by a suicide) because, really, the writer actually has nothing to say. The ending is almost a "*beep* you" to the audience after having endured the film—as if to say "keep doubting" there is any meaning to it all beyond pure exploitation!
I read an article long ago in which the "auteur" claimed he just had an inspiration of the violent home invasion scene and built a film around that. And so the ridiculous and vile padding around this disgusting inspiration is all this movie is.