Mothers, those wonderful ladies who ruin so many children with their demented ways! Let us take a moment to thank them all for their domineering religiosity, their incestuous lust, their Puritanical hatred of sex, their whoring about with a cavalcade of strange men, or just their all-around emotional inaccessibility - all the wonderful things that have given so many screenwriters so much to work with over the years. Happy Mother's Day to all the moms out there, and I hope your sons never wear your flesh like a housecoat.

First, the disappointing news: there's no indication that Mother's Day actually takes place on Mother's Day. One would not think that a single line of dialogue to that effect buried in one scene would have been such a big deal, but one would have been wrong.

Then again, only two (if I recall correctly) of the Friday the 13th films makes any special point of taking place on a Friday the 13th, so we can hardly blame Mother's Day too harshly; besides, the title really was right there for the taking, especially in the heady days of 1980, when the slasher film was still a mewling infant and "event" horror films - the likes of Prom Night, New Year's Evil, and of course Friday the 13th itself, all of them undoubtedly taking their cue from Halloween - were all the rage. So no, not mother's day. Big deal. It's still a horror movie about an insane mother and her insane psycho sons, and I am sure we can all live with that.

The second news, and you tell me if it's disappointing: despite its release date and other details of its pedigree - not least of which is location photography in the New Jersey woods, right in the same area where F13 was being shot around the same time - Mother's Day just refuses to let itself be a slasher film, even in the funky way of some early examples of the form where they were still working the kinks out of the formula. To tell the truth, I am not certain that I can even pinpoint which if any specific subgenre the film belongs to: pretty much all of the opening 40 minutes certainly make it seem like it's going to be a nice straightforward slasher, and then it suddenly makes a dodge in the direction of ripping off pseudo-slasher The Texas Chainsaw Massacre, spends an exhausting and protracted scene acting like it's going to be an extraordinarily early example of the torture porno, before a final act that I honestly don't know how to quantify at all: it's somewhat of a rape-revenge story in the Last House on the Left vein, but that doesn't fit terribly well, either. It's sort of alarming that a horror film from 1980, particularly one as magnificently cheap as Mother's Day, could manage to spend so much of its running time keeping ahead of me, and I don't even think it's because director Charles Kaufman and his co-writer Warren Leight were trying to be sneaky: it's more likely the case that the filmmakers didn't know they were breaking any rules simply because the rules didn't quite exist at that point. It would take the subsequent decade of chintzy American horror to set up all the strict rules that Mother's Day never plays by, and thus it is, oddly, more transgressive now than it would have been when it was new.

And since I sort of glossed over it, let's return: yes, director/co-writer Charles Kaufman, the brother of Lloyd Kaufman, who co-founded Troma Entertainment six years before Mother's Day was released. And, indeed, this just so happens to be a Troma film. Do you not know Troma? I'm tempted to say you're better off: but that would be snippy and unfair. And my apologies for this aside to those who do know Troma, but in short, the company specialises in very tacky, very trashy, very tongune-in-cheek horror comedies with lots of nudity and gross-out makeup effects and barely even the pretense of being an actual horror movie; they are specialists in making films deliberately so bad they're good. In my experience, they are typically only so bad.

Troma's ascendancy came largely throughout the mid-1980s, well after Mother's Day, and this is the first thing the latter-day viewer needs to be aware of right away: the film is absolutely not characteristic of the company's future work. And this, like the film's unconventional plotting, is almost entirely an accident of history that this should be the case. Even so, it threw me to come in expecting a snotty, over-the-top parody and get instead something as nasty in spirit as this, even though the sprawling redneck caricatures of the main villains certainly puts the film within the wheelhouse of Troma's later work, for the artless broadness with which they are presented, if nothing else.

The film opens with the final minutes of an inordinately '70s-style self-help seminar called E.G.O. - Ernie's Growth Opportunity - where people are encouraged to hug and kiss their neighbors in celebration of how much everybody has learned about self-expression and connecting with fellow human beings. Actually, it opens with a "ooh, scary, thriller!" chord on a synthesizer, which continues to play over a tracking shot of a roomful of people staring with dead-eyed intensity off camera, and these turn out to be the E.G.O.-tists. It's a strange gambit that works - and this is true of many things that happen over the course of the movie, where tonality is bopped around and very, very often the things that are happening, the way they are shot, and the sounds we are hearing all seem to be operating in three entirely different genres. Following all of this, anyway, an old woman (Beatrice Pons, operating under the name of Rose Ross) offers a ride to a pair of young people (who I take to be Marsella Davidson and Kevin Lowe), and as she prattles along blithely, Kaufman devotes so much energy to making the kids seem shifty and threatening that it's instantly obvious that they're up to nothing at all but looking for a ride home, and the woman will kill them both. Actually, she does not: that job gets farmed out to her two sons, profoundly dumb Ike (Frederick Coffin, as Holden McQuire), and almost as profoundly dumb Addley (Michael McCleery, going by Billy Ray McQuade), who seems less dumb because unlike Ike, he does not have a dead eye and shitty teeth. The important part of all this, by the way, is not who kills who and what their names are, but that Ike and Addley are unnervingly anxious to make sure their sainted mother approves of just how they go about killing their victims.

It will be quite a while before we visit with our psychotic backwoods friends again, for now we get to meet the Rat Pack of Wolfbreath College: three women all around thirty, who were thick as thick can be back in the day, defending one another from terrible boyfriends, domineering parents, and general boredom: Trina (Tiana Pierce), who lives in Beverly Hills and is some undefined way one of the beautiful people always giving and attending parties and generally being seen with and by important cinema folks (she is introduced at a party scene full of vapid Hollywood "deep" types that recalls, though it obviously does not match, the L.A. sequence of Annie Hall); Abbey (Nancy Hendrickson), living in cramped Chicago apartment with her unspeakably cruel hypochondriac mother; and Jackie (Deborah Luce), a New Yorker who makes the most spectacularly bad choices about men you could imagine. Once a year, these three women get together to go on mystery trips, in which only one member of the trio knows where they're headed or what they're doing there until they've arrived. This year, it's Jackie's turn, and she wants go go on a camping trip in the New Jersey woods. First, of course, they have to pass by a creepy convenience store manager (Scott Lucas), who warns them to stay away from Barons Wilderness. Though after they manage to destroy his shop, he's a lot less concerned with sending them off to their demise.

And from here things go, in the abstract, much as you'd expect: the girls show up, camp, reminisce, fight, poke about in the wilderness, and finally stumble across Ike and Addley and their mama, and proceed to suffer unendurably until anyone not dead manages to escape and plot vengeance. In the details, though, it's actually rather exceptional: if nothing else, I was pretty certain from the instant the three women were assembled who the Final Girl was, and that the filmmakers weren't even trying very hard to disguise it; and I was about as wrong as it is possible to be wrong. Besides, there is the whole manner of the film's dive through tropes and moments that come from a whole bunch of related but ultimately distinct film subgenres, making it hard to accurately pinpoint Mother's Day through every last one of its twists if only because it's never completely obvious what game it's playing, let alone what cards it's holding.

It is not, mind you, a good film. I would not want to risk burying that very significant truth. Rape revenge is already a spectacularly tricky genre to pull off well (in fact, I can't confidently state that it ever has been) because it is so easy for it to race straight into the most dubious kind of exploitation movie hell, and while I can name plenty of films that are just straight-up ickier than Mother's Day - The Last House on the Left itself being among them - that hardly implies that Mother's Day itself is in anyway restrained or classy or intelligent about its subject matter.

Even without bringing morality into the mix, there's plenty that the film gets wrong: the killers are a blend of slapstick and menace that could have worked, unchanged, in a different movie, but in the presence of a largely realistic group of protagonists, that kind of proto-Troma tasteless wackiness crashes with a thud. And there is barely a single really credible performance in the whole movie: some actors, like Hendrickson, Luce, and Pons, have plenty of individually good moments, but Pierce is far too willing to play Trina as a completely superficial bitch, and given how thoroughly the two male killers aren't even supposed to be anything but clichés and stereotypes, it's hardly surprising that Coffin and McCleery play down to the material.

But, even if it's a bad film - and I think it is - there are enough incidentals that aren't just good enough, but absolutely brilliant, that I can't help but want to give Mother's Day a pass. For starters, Charles Kaufman is actually a pretty decent director, and plenty of the stalking around scenes in and near the killers' house are honestly thrilling, something very few early-'80s horror films can even start to claim. The screenplay is deceptively clever, using foreshadowing all over the place in the opening sequences that seems, at the time, to just be character-developing detail: and for that matter, the script's characterisations are absolutely earthshaking, given how robustly blank most horror movie protagonists are. Not here! The performances let the script down, but Trina, Abbey, and Jackie are as fully fleshed-out and believable as any other set of victims in any American horror film I've seen between Halloween in 1978 and A Nightmare on Elm Street in 1984. A healthy chunk of the movie's running time isn't even trying to be a horror movie, in fact: most of the scenes of the women on vacation functions more at the level of a chamber drama about adult friendship than any other genre.

What impressed me most about it, though, is something so pointless and weird I hardly ought to bring it up: the use of trademarked material. Mother's Day was made for hardly any money by a company that barely existed, which meant that to some degree, nobody was paying attention: and Kaufman and company abused that fact by populating the film with lots of actual products and TV audio that feels like the real world, not a movie version of it. At one point, the psycho boys are woken by a plastic Sesame Street alarm clock, and hearing Big Bird cheerfully encourage them to wake up and face the day - when we are well aware that "facing the day" means raping the two girls they have tied up in their workout room - is about as incongruous and creepy as anything that I think I've seen in a horror movie of similarly tawdry provenance. And I'm willing to bet that Children's Television Workshop did not approve of their character being used in that manner; if I were them, I wouldn't either. But since I am not them, I can report that it works: it is one of the most altogether disarming moments of a film that's already keeping the viewer more disoriented than not. The heart of the film is generally unpleasant and dumb without being insightful, but it's this kind of unexpectedly effective detail around the edges that sticks, and raises Mother's Day, ugliness and all, at least a step above almost all of the other equally obnoxious, disreputable horror cinema of its day.

Body Count: 6, and though I do not want to give away the ending, it is nonetheless far too notable not to say - this excess verbiage is so you can change your mind before I throw out a spoiler - as I was saying, it is remarkable and powerfully unique that fully half of the body count in a 1980 horror film consists of the three killers themselves.