The nameless, shape-shifting horror that stalks the blond, 19-year-old Jay (Maika Monroe) in David Robert Mitchell’s cool, controlled horror film, "It Follows," might be described as the very incarnation of paranoia. The menace, which only she can see, takes any number of forms, from a naked man standing on the roof of a house to an unsmiling old lady heading purposefully in her direction. When it appears, it is usually first glimpsed from a distance, walking slowly toward her like an expressionless zombie. Although Jay repeatedly flees, she can never shake the sense that it is out there somewhere and knows her precise location.

‘It Follows’ Rated: R Opens Friday at Kahala 8

The second feature film by Mitchell, the director of the 2011 cult film "The Myth of the American Sleepover," "It Follows" is set during autumn in a Detroit suburb. The place is so depopulated that the empty streets and darkened houses evoke a ghost town evacuated in an emergency. Except for a few scattered people, Jay and her teenage friends are the only remaining local residents. There are no parents in sight.

It takes a while for Jay to convince her friends that the danger isn’t just a figment of her imagination. But as the ominous portents accumulate, the group, which includes Kelly (Lili Sepe), Yara (Olivia Luccardi), Paul (Keir Gilchrist) and Greg (Daniel Zovatto), stands by her. Unlike the daredevils and vixens of slick Hollywood horror thrillers, these are everyday teenagers. The shy, pensive Paul, who has had a crush on Jay ever since they shared a kiss many years earlier, is the most memorable.

"It Follows" opens nearly a year after winning the Next Wave award at the 2014 Cannes Film Festival. Its acclaim derives from its masterly manipulation of mood by its cinematographer, Michael Gioulakis. The deadly menace, which seems to emerge from your peripheral vision, is initially hard to discern, but as it draws closer, never quickening its step, you sense its grim intention.

Rather than breaking new ground, "It Follows" recycles familiar teenage horror tropes — a girl alone in a house, evil forces banging on a door — but its mood is dreamy. Seldom do you feel manipulated by exploitative formulas. The violence, when it comes, is sudden, and the camera doesn’t linger over the gore.

Jay’s troubles begin after she sleeps with her new boyfriend, Hugh (Jake Weary), who, after their lovemaking in his car, ties her to a chair under a bridge and explains her predicament. From him, she has caught a supernatural version of a venereal disease. Having sex with someone else is the only cure, if cure is the right word.

The explanations for almost everything that happens are intentionally enigmatic and sometimes completely mystifying. In the most elaborate set piece, Jay dives into an indoor swimming pool, which her friends encircle with electrical appliances. But why? For protection?

"It Follows" abides by a principle that few horror movies have the courage to embrace: The unknown is the unknown. Clues to the source and motives of this menace are dropped, but they don’t add up. Like the evil in a David Lynch horror film, it is out there in the night, waiting to get you.

© 2015 The New York Times Company