CANNES -- David Robert Mitchell's "The Myth Of The American Sleepover" was a low-key, low-fi charmer that came out of nowhere a few years ago. The title struck me as perhaps a wee bit on the ambitious side, but the film wasn't out to make grand generational statements. It was just a well-observed film about the sort of night that is important to teenagers precisely because of how loose and free and dangerous it feels, and it marked Mitchell as a guy who had something to say, and a very particular way of saying it.

"It Follows" is his second feature, and it feels very much like it is a companion piece to "Myth." It takes place in the same sorts of neighborhoods, on the same sorts of streets, and many of the scenes play out in that same sort of dreamy loose manner, the way many real conversations play out for teenagers. The difference is that Mitchell's got a very different goal in mind this time, as "It Follows" is an unabashed horror film. There's something really compelling about watching what feels like his first film suddenly erupt into a supernatural nightmare, and it feels like Mitchell's just as much of a soft spot for Carpenter's Haddonfield as he does for Linklater's Austin.

The film opens with a girl running out of her suburban house. It's dusk. She's scantily clad and gripped by panic. She runs in a circle, not quite sure where to go, what to do. When her father asks if everything's okay, she runs back in the house to find her car keys, then drives away, still struggling with her fear. She goes to a lonely beach. She sits alone, calls home, tells her parents she loves them. And when the sun comes up, the light falls on her broken, lifeless body.

In some ways, "It Follows" feels like an urban legend you've known your whole life, but it's actually a horror idea that is fresh, just different enough that it becomes exciting to see how it's going to play out. After that opening, things shift back into a lower gear for a little while, and we get to know Jay (Maika Monroe, who was so good in the Sundance midnight movie "The Guest" this year), a teenage girl who is just starting a new relationship with a guy named Hugh (Jake Weary). She likes him, and after a somewhat odd date, she finally sleeps with him, a sweaty, spirited encounter in the back seat of his car. As she lays there enjoying the afterglow, Hugh chloroforms her and drives her to a remote location. It's not what you think, though. Hugh doesn't try to hurt her. He just wants to show her something. It seems that Hugh has passed something to her, and now, a hungry vengeful thing that was following him has been given a new target, and if she expects to survive, she's going to have to find someone to sleep with and pass it along again.

It's certainly not a new idea to connect horror to teenage sex, but Mitchell's creation here is uber-creepy precisely because of how simple it is. It never moves at faster than a walk, so you can definitely outrun it, but it also never stops coming after you, and no matter where you go, it will find you. It can look like anyone, as well, so there is a paranoia that begins to set in after a while, and as Jay struggles to make sense of what's happened to her, she begins to lose grip on her sanity, no matter how hard her friends Paul (Keir Gilchrist), Yara (Olivia Luccardi), Kelly (Lili Sepe) and Greg (Daniel Zovatto) all try to help.

As with many horror films, this is a movie where teenagers seem to exist in a largely parent-free world, and as "Myth" demonstrated, Mitchell understands that world. Because he's so good at summoning up this very mundane reality, it feels every weirder and more invasive when something horrific happens in it. At its best, the film has moments that are creepy and that work on some strange primal level. Many of the manifestations of the angry force in this film are played by people who are oddly visually striking, like an enormously tall and oddly-shaped man or a guy with a weird pinched rodent face and jug ears. They are not overtly terrifying, but it's more a matter of how unsettling they seem when they appear in places they simply should not be.

Mitchell's less successful in the staging of a few key set pieces, where he actually relies on FX to make the supernatural more overt. Perhaps his best single FX gag is a direct nod to a similar gag in one of the "Paranormal Activity" movies, but the majority of them are unsuccessful, to put it kindly. I also feel like he really botches a scene that takes place in a pool, where the kids are determined to electrocute. They plug in something like two dozen appliances around the pool. It looks like they're cooking up this big plan, and in the end, it seems like none of that matters at all. It's a dead end.

The film looks like it was a micro-budget production, but that seems to play to Mitchell's strength, getting really solid performances that look mundane but that are actually nuanced. I suspect we'll see a lot more of Mitchell in the future, and he seems to me to be a guy who has a very clear voice. He's only going to get better as he makes more films, and that's saying something. He may not have the technical polish of some of the other directors who have work here this year, but he's already figured out who he is, and that's invaluable.

"It Fellows" is still screening for potential buyers at Cannes.