A friend confessed to me recently that this was the only film to have given him, in adult life, a proper wake-up-sweating nightmare. I don’t think I have ever had a nightmare quite as scary as this film – a modern classic of fear to be compared to something by a young Carpenter or De Palma.

It Follows is from the American director David Robert Mitchell, whose 2010 debut movie, The Myth of the American Sleepover, was a gentle, unthreatening drama about teens and platonic crushes. That was Dr Jekyll to the snarling Mr Hyde of this new one. It genuinely is disturbing.

What Mitchell has given us is a contemporary reworking of ideas from MR James; in particular, his 1911 ghost story Casting the Runes. Jay (Maika Monroe) is a high-school student who has just started to date a nice enough guy called Hugh (Jake Weary); the rest of the time she hangs out with her sister Kelly (Lili Sepe), Yara (Olivia Luccardi) and a shy childhood friend called Paul (Keir Gilchrist) who has long had a hopeless crush on her. Jay’s normal sex life takes its normal course, but then she finds out, too late, that she has been inducted without her knowledge into a supernatural death cult. The sex act means that she will be followed, at a zombie’s walking-pace, by a demon that only she can see, and which will kill her. The only way she can get rid of her pursuer before this happens is to have consenting sex with someone else, and so pass the curse on to them. Her agonies of horror and indecision are compounded by the presence of Paul, piningly ready to protect the person he loves.

The film team review It Follows Guardian

I love the title: a clear, deadpan, pitiless description, rather like the insect horror They Nest (2000). They did, and it does. The action of It Follows, with its viral spread of horror and shame, could be read as an abstinence parable or a herpes nightmare or a metaphorical account of Aids. But the point is that the It Follows demon is a satirical inversion of this literal case. Counter-acting the harmful or fatal effects of a sexually transmitted disease means stopping what you’re doing, not persisting. But it also means tracking down previous partners to warn them. So in this case you become the follower, and you have to be discreet about it – invisible, in fact, like the nightmarish figures in Mitchell’s movie.

It Follows taps into something else about sex and intimacy. I found myself thinking about Simon Rich’s short story The Haunting of 26 Bleecker Street, in which a careworn priest tells a lovelorn young man that the ghost of his ex-girlfriend can only be exorcised if he has sex with someone else. Maybe the truth is that sex can often create a malaise of anxiety, a loss of self that can only be alleviated or reversed by another sexual contact. And so it follows and goes on, and humanity is kept alive with a chain-letter of fear, fending off death with desperate replication. (Although death is always present – one character broodingly reads Dostoevsky on her cute shell-shaped Kindle.) And the horrible, unspoken question in It Follows is … who first explained the rules at the very beginning?

A sinister spell … It Follows

The movie reminded me of Abel Ferrara’s vampire nightmare The Addiction (1995), as well as John Carpenter’s Halloween (1978), which is an obvious inspiration, with its clamorous synth score. There’s also a touch of Reefer Madness (1936), the self-satirising propagandist film about the spread of drugs among young people. Everything takes place in a bland, suburban world of broad avenues and handsome detached houses, but without any sentimental or Spielbergian glow; it is seen in a perennial dusk. They live in Detroit, where the ruins cast their own sinister spell.

Larry Clark is another indirect influence. Mitchell captures something of the same listless, affectless world of young people hanging out, and he has a way of eroticising and fetishising the details. Older people are present only at the margin. There is a moment when Jay, at the height of her fear, just gazes down at some strands of grass that she has placed over her skin, and there is a something dumbstruck in the way Mitchell’s camera captures this simple image: it looks weird, alien, almost evil, like everything else around her. Mitchell brings off some sensational setpieces of fear and suspense. I can’t remember when I was last so royally freaked out in the cinema.