Jake Weary and Maika Monroe in It Follows.

A young woman pays the price for sex in a car in a very big way in It Follows, a creepy, ghoulish, unrelenting horror film from writer-director David Robert Mitchell.

Taking more than a few cues from John Carpenter’s Halloween and the zombie works of George Romero, Mitchell is tuned into the sort of stuff that makes filmgoers squirm and sweat. The movie, reportedly based on one of his own nightmares, combines voyeuristic camera work, eerie soundtrack vibes and fine acting to result in one of the best old-school horror films of the past decade.

Jay (Maika Monroe), a shy high school girl, cools off in her backyard pool while the neighborhood kids spy on her. She’s got a big date with the dreamy Hugh (Jake Weary of Zombeavers), and is anxiously anticipating it. The young couple take in a Cary Grant movie, indulge in some people-watching games, and then have sex in the backseat of his car. She barely has time to take in the loss of her virginity before she’s sucking on a chloroform rag.

Turns out Hugh had an agenda beyond sex: He’s carrying some sort of curse, and the only way to pass it on is through intercourse. The curse involves an unstoppable force that can take the shape of any human, be it an old naked man or one of your parents. That force is not only out to kill the cursed individual; it’s out to kill the cursed individual in a very violent way.

The nightmare kicks in fast for Jay, as a never-ending chain of expressionless people pursues her. The sight of humans simply walking forward hasn’t been this scary in a long while. The aforementioned Carpenter did it well in the original Halloween with Michael Myers, in his white mask, walking like a menacing robot toward his prey. Mitchell uses people of all ages, shapes and sizes as his monsters—and the more normal they look, the more frightening they are to watch.

The shape shifting “monster” is highly effective device: You will find yourself constantly scanning every frame of this movie, evaluating every human being that appears. Crowd shots are especially unnerving. There are times where the “monster” is fairly apparent, and others times when it is vaguely visible in the back of the shot. In short, you don’t ever feel safe watching It Follows.

Of course, there is also a “loss of innocence leads to danger” element here: Not only does Jay lose her sense of safety and well-being after her first sexual encounter; she is forced into a form of promiscuity as she frantically tries to pass the curse along. Characters in this film who would otherwise be generous, caring types wind up hurting and cursing others out of fear and dread. Once they are faced with terror, they act in inarguably selfish and psychopathic ways.

This is mind-bending material, and it marks Mitchell as a filmmaker who knows how to go deep in a genre that is often quite shallow. The finale actually feels a little big for his lean indie film, but it’s still an effective conclusion. I’ll also note that Jay’s friends cannot see the monsters pursuing her, which leads to some good sequences of people being tossed about by invisible forces.

Cinema has had few true horror standouts in recent. (Last year’s The Babadook is a modern classic, and Afflicted was a fun spin on the vampire genre.) I would place It Follows at around the same level of The Babadook: It’s a modern classic. Go see the film, and be prepared to have a love/hate relationship with Mitchell: He’s going to give you a nice, scary time at the movies—and nightmares in the days after.

It Follows is playing at theaters across the valley.