It may be shamelessly derivative of countless other horror films, it may be the latest in a long run of American remakes of foreign movies deserving of a proper release, and it may be suspiciously timed to feel like nothing but a mercenary knock-off of Cloverfield, but this much about Quarantine certainly shocked me: it is not completely worthless.

Admittedly, I have not seen [Rec], the 2007 Spanish film from which Quarantine was derived, and it seems fairly likely that the best parts of the remake are debased copies of the best parts of the original. But even with that caveat, the modern American horror movie is such a lame creature that it doesn't really take all that much to impress me. I mean, Quarantine is rated R! An R-rated horror movie! Can you believe that shit?

The plot goes a little bit something like this: On 11 March, 2008 (a date provided to us only in the film's advertising campaign), Angela Vidal (Jennifer Carpenter), a Los Angeles TV news figure whose beat consists primarily of those maddeningly cheerful human interest pieces about meeting the people in your neighborhood, and her cameraman Scott (Steve Harris), arrive at a fire department to shadow firemen Jake (Jay Hernandez, arguably the most recognisable face in a cast full of people you think you might have seen once in that thing) and George (Johnathon Schaech). After a while wandering the station and having fun sliding down that pole that they slide down, Angela gets the break that she's been hoping for the whole time that she and Scott record banal interviews and get unimaginative B-roll: a for-real emergency call, something to do with a woman in a locked apartment screaming at the top of her lungs.

Cut to: one of a thousand anonymous L.A. apartment buildings, where the woman in question is found drooling and mumbling, before she unexpectedly starts attacking the firemen and the two cops who were already at the scene. That would already be worrying enough, especially when George and one of the cops end up with potentially fatal amounts of blood loss, but it's nothing compared to the unexpected arrival of the Centers for Disease Control, who lock the building down, cut off the cable and phone lines, and announce to the world that the building has been evacuated, and there's nothing to see (a fact that the residents only learn through an ancient television with soon-to-be-obsolete rabbit ears). The CDC may have a point; after all, there's something causing all the people the woman came in contact with to start manifesting very similar symptoms right before they turn cannibalistically violent themselves, and the dozen or so people left in the building are rather quickly reduced to a number far south of "a dozen or so".

The difference between Quarantine and just any old retread of The Crazies is that every last frame of footage we see is shot from the perspective of Scott and his trusty news camera. The whole "found footage" trick is already quickly turning into a cliché itself, but at least Quarantine manages to justify its gimmick better than Cloverfield or Diary of the Dead (or the granddaddy of them all, at least in America, The Blair Witch Project). While most films of the type tend to invent increasingly squirrely reasons for keeping the camera in the hands of some character or another in spite of the most basic survival instincts (especially present, to an almost embarrassing degree, in Diary), Quarantine has two reasons, both simple, and both fairly believable: at first, Angela expects to be rescued and she wants to make sure that Scott records a full accounting of all the civil liberties being violated; later, once the really deep shit begins and that reason seems silly at best, the camera provides the only working light source to be found in the building.

Here is what Quarantine is not: an effective scary movie. Like an unfortunately large number of genre filmmakers in the last 30 years, John Erick Dowdle (whose similar "found footage" serial killer flick The Poughkeepsie Tapes has been waiting on a release date for well over a year now) willfully and blindly conflates "horrifying" with "gory", nor does he really seem to grasp the concept of the slow build - no, every scare is blatantly telegraphed, and pretty much the only card up the director's sleeve is to quickly pan over to a pasty-faced ghoul with blood all down its front.

But despite that fact, and despite Quarantine's theft (narratively or visually) from nearly every film in the "zombies who are actually infected normal people" genre in the last ten years, there are parts of the film that just plain work, no matter how much it doesn't seem like they should. The opening is one of the parts; curiously for a horror movie, it's actually the best part of the whole film, those first scenes that consist of Angela and Scott enduring the indignities of being the cutesy part of the early evening news. I'm not kidding when I call it one of the best commentaries on the media in any movie this year: all the effort these two people have to waste to get enough footage to put together a piece that will probably last for all of 90 seconds once it gets to air. Then there's the matter of Angela, plainly hired first and foremost (despite her obvious skill and crazy devotion to getting the truth) for her perky tits. It's tiny but unmistakable, the way that she cringes inwardly under the firemen's leers, even as she knows damn well that her job is essentially forfeit the moment that she voices a complaint over something so trivial as being converted into a smiling sex object.

Once we're in the actual movie, though it's mostly a routine trek through the usual zombie-style landscape, a few moments pop up as being better than the genre usually requires. Looking at the structure of the story, it's hard not to suspect that Dowdle and his brother Drew, in adapting the screenplay, knew that most of the audience has seen enough movies just like this that they could skip a step every now and then, and let us naturally fill in the blanks. This accounts, I think, for the film's very quick ending, which leaves many gaping questions apparently unfulfilled; except that if you're looking closely in a couple of scenes (and not even that closely, really you just have to be literate), and you know how experimental viruses come to be loosed in movies like this, there shouldn't be anything left unanswered once the credits start rolling. We could debate whether that's narrative parsimony or just flat-out laziness, but I have to be honest, I kind of liked having a horror movie that assumed I could figure things out on my own, even if the film itself hardly counts as the model of intelligence and creativity.