Sex Changes Everything: “It Follows”

“IT FOLLOWS” IS A MOVIE ABOUT SEX, from the first itch to the last consequence and nearly everything in between. It’s not about affection. It’s about an animal urge that dominates the lives, in different ways, of young men and women — part Urban Legend, part Grimm Brothers — made manifest in a lumbering, inexhaustible and sexually transmitted ghoul.

It is wholly successful.

“It Follows” is so uncannily smart that it plays almost as a mistake, like outsider art — something found in Henry Darger’s closet. The strokes are broad, the dialog infrequent and the plot, such as it is, intractable. For writer/director David Robert Mitchell, there is no elegant or clever way out, which is precisely the point.

Set in the first-ring suburbs of Detroit — the city’s decay follows these kids, too — “It Follows” plays an interesting game with time and place. It trades in the horror tropes of the 1980s, setting the tone with a general set piece that recalls both “Sixteen Candles” and “Re-Animator,” and the characters talk on land lines and drive American station wagons. We know the setting is contemporary only because the group brainiac is reading Dostoevsky’s “The Idiot” on a mobile device.

This anachronistic lens allows Mitchell to subvert the old slasher-film trope — sex will kill you — to great effect, mostly by sucking the life out of his protagonists before the credits roll. Once the acme of recalcitrance, sex here is inevitable and joyless. In “Black Christmas” (1974) or “Friday the 13th” (1980), it wasn’t the sex that killed you, it was a society bent on squashing your buzz. The menace in “It Follows” is less contextual, and therefore more real. It’s not sex but the wheels it sets in motion — the way it changes everything and nothing.

After the quietly crushing Peter tests a cure by having sex with his first love, Jay, he asks, “Do you feel different?”

“No,” she says. “Me, neither,” he answers.

Jay, Peter and their friends are not rebels; they’re an aimless bunch killing time with TV and community college before … whatever. Heroine Jay is introduced lazing in her above-ground pool in Livonia, enjoying her first fall out of high school, the graduate with a vaguely unhappy past and, we soon learn, a future that will … not … stop … chasing … her.

For whom does this ghoul work? How exactly is it unleashed? These questions go unanswered. In fact, after a half dozen couplings, it becomes less and less clear for whom the menace lurks. The final frame, a bittersweet snapshot of another bad relationship and the danger that awaits, is the only explanation needed.