Basically, Splice is one of the most confounding horror movies I've seen in quite a long time. Parts of it work magnificently well, parts of it work magnificently well while being incredibly hateful, and parts of it are just plain stupid. There are going to be a lot of people who see it, and hate it, and can't wait to tell you exactly what parts of it they hated the most. They're going to be completely right, too. But for myself, I found that it worked in a very weird way, even as it sometimes made me feel very unhappy with myself for liking it.

Problem #1 has nothing to do with the film, but with its marketing: it's been called both a creature feature and a body horror movie, and while it arguably meets the dictionary definition of those two categories, neither one of them seems remotely accurate. It's essentially something very different, an unusually pure "don't tamper in God's domain" mad scientist narrative, disguised in art-house drag, and while there is a creature (an extraordinarily well-realised one), and there is a good deal of ickiness from the way that the creature is a perversion of the human form, this is, through and through, modeled on Frankenstein. And for those of you who've read Mary Wollstonecraft Shelley's hugely influential novel, you perhaps recall that it's relationship to "horror" in the modern sense is tangential at best; it's hard to imagine anyone being scared by the book, unless it's that they're the kind of person terrified by long blocks of prose expressing convoluted philosophical positions. So it is with Splice, which is horror in a much more theoretical sense than we're used to in modern cinema - up to a point, but I'll get into that - and much of what makes it most fascinating is the way that it toys around with what "horror" means at the end of the first decade of the 21st Century.

"Horror" has come to be defined, like "comedy", as a genre about the emotion it produces: fear, in this case. But that's not the only way to define it; it might not even be the best. And like "comedy", which can be defined as a story which could end in the death or other suffering of the protagonist, ending instead with happiness and reconciliation (hence something like the nasty and almost entirely mirthless Measure for Measure being counted among Shakespeare's comedies), so can "horror" be defined according to the structure of its plot. Classically speaking, horror goes something like this: the opening situation finds the protagonist happy and stable. Something unnatural - not necessarily paranormal, though it helps - causes the protagonist's life to become upended for the worse, eventually resulting in existential danger. The protagonist may die, or not; it doesn't really matter. What matters is that a happy life has been interrupted by something uncanny, and it is terrible.

We can define it more simply still: horror is the genre of small-c, non-political conservatism; it is the genre of wanting things to not change and being threatened when they do. And let us now return to Splice, since this is supposedly a review of that film: the theoretical definition of horror I just gave is unusually clear in this movie, much more than is typically found in modern horror (which has anyway become hideously debased in the past six or seven years). There's a long tradition of anti-science, anti-progress narratives in horror, sometimes good and sometimes ill; but it's been a while since any movie has come out that states so plainly - so banally, even - that scientific advance is evil, evil, evil.

Splice concerns two scientists, Clive Nicoli (Adrien Brody) and Elsa Kast (Sarah Polley), who are living together and very conspicuously and specifically not having a child (by the way, odd character names, like "Clive" and "Elsa", are usually a sign that the name Means Something. In this case, I am virtually certain that the names are a reference to Colin Clive, who played the title role in Universal's 1931 Frankenstein, and Elsa Lanchester, who played Mary Shelley in the 1935 sequel Bride of Frankenstein - that is, they're named, in a very slantwise way, for the two creators of the most famous abomination in the eyes of God in literary history). They work as genetic scientists, splicing together bits from different animals' DNA to somehow get medical knowledge from it - the exact nature of the science doesn't matter at all. So far, their great successes are a pair of blobby things nicknamed Fred and Ginger: a male and female matched set, though we're pointedly told that Fred is the more advanced of the two.

Frustrated by the lack of ambition displayed by their twerpy boss William (David Hewlett), Clive and Elsa take things to the next level one night after hours, adding human DNA to the slurry that made Fred and Ginger, just to see what happens. Thereafter, another blobby thing is found growing at a much faster rate than either scientist expected, and Clive is all ready to kill it; but Elsa stays his hand. In short order, a being is born, looking rather too human for logic to explain it (but the exact nature of the science still doesn't matter), and it grows into a female at a wildly accelerated rate, and Elsa, with feelings much more affectionate and maternal than they had ought to be, methodologically speaking, names the thing Dren (played, as a child, by Abigail Chu, and after maturity by Delphine Chanéac). And here's where things get really thick and clotty with musing and themes and character analysis, and thus I end my synopsis.

Almost as much as Splice hates science, it hates mothers. A more urgent, incensed sideswipe against the maternal instinct I haven't seen recently, if ever; for in short order we learn (to spoil something that you can guess very easily) that Elsa used her own DNA to create Dren, a huge ethical no-no, and that this strange half-human creature that she and her partner must hide from the world is her stand-in for the children that she and Clive aren't going to have anytime soon. There is not a single moment in which Elsa's actions aren't clearly misguided; the film makes every effort to blame her for as much as possible, and punish her in the most cruel, hamfisted way in the end (though by this point, Clive has done some equally terrible things, and his punishment is pretty cruel itself).

One assumes from the evidence of the film that director and co-writer Vincenzo Natali has some pronounced mommy issues, for at times the narrative becomes little more than a screed against mothers in particular and women generally. And yet, it never feels completely bothersome to me, which I think is due almost solely to Sarah Polley, one of the greatest English-language actresses working right now (and based on the evidence of Away from Her, one of the most exciting new indie directors to keep watching). She's too smart to play Elsa as the basket of self-contradicting impulses that the writer made her; she's also not self-loathing enough to buy into the maddeningly pervasive misogyny of the script. Of course, there's only so much one performer can do when the whole of a movie is stacked against her, but Polley's characterisation of Elsa manages to vanish away far more of the role's most gaping problems than you'd think possible, playing the film's apparent invective against womanhood solely as the individual impulses of this one person, never playing up the gendered parts of the script when she can possibly avoid it.

Even she's helpless in the face of the final act, when Natali and company apparently realised that their horror film was much more situational and intellectual than visceral, and so things suddenly fall apart in a standard-issue "run around screaming" marathon, involving still more dodgy science, still more bitter anti-mothering, mixed in with a nice dollop lambasting male sexuality, in a couple of different ways. But that's the ending. Let me jump back to the beginning, because besides Polley's performance, there's something else that just absolutely works in Splice, and that is Natali's direction: especially in the first fifteen minutes, which consists of absolutely nothing but following Clive and Elsa around the lab. It's a sequence made up of some of the most truly unexpected shots you can hope to see in a summer movie, with all manner of narrative clues and important flourishes of character and world-setting hidden in plain sight in very crowded frames. Taken as a whole, Natali's treatment of the material makes it that much clearer that Splice isn't meant to scare you, but to present an idea about human behavior that's none too optimistic. Or accurate, but still, the presentation is sufficiently energetic, filled with a great deal of what I take to be deliberately campy humor (people complaining at how easy it is to laugh at the film are, I think, playing right into Natali's hands; he is deliberately mocking the characters, whom he plainly doesn't like. This is unusual in American horror, outside of the slasher/torture ghetto, and it can make the film hard to process, given our assumption that we're "supposed" to sympathise with Clive and Elsa), that its complete removal from anything like humanity doesn't bother me too much; the film is captivating in its own way, though by no means a great work. It's more fascinating than anything, a collection of observations that sometimes make no sense, and sometimes offend, but the cumulative effect is electric.

Lastly, a word of the most outlandish praise for the creature design: Dren is one of the most singularly memorable movie monsters in a very long time. It would seem that her design was the responsibility of one Amro Attia, and if so, he needs to get more work this very minute. Though there are some very silly moments, even at her goofiest, Dren looks absolutely convincing, human enough that the non-human elements are skin-crawling; and Chanéac's performance goes a long way towards cementing the uncanny perfection of the character. She's not as key to the film as the genre would have you expect - it's far more about what Dren's presence does to Clive and Elsa psychologically than what she does in the plot - but it's enough to justify Splice despite all of its thematic blind alleys.