After getting intimate with her charming new beau, a young woman is ambushed by a crazy lifestyle change: the sudden appearance of a creeping, faceless terror that tirelessly shambles behind in a slow, dogged pursuit. The rules of its game are laid plain by the boyfriend, who lured her in with the promise of a stable relationship to break his own date with the stalking menace: find another sexual partner to pass it on and don't let it catch you in the meantime.

Even ignoring the potent metaphorical possibilities (and there are oodles of those), this is a smart, fascinating idea. As the girl and her friends probe the quirks of her new curse, test its limits, narrowly escape its vengeance, the tension simmers, bubbles and boils in anticipation. It's always fun to toy with the rules of such a weird world, and the answers _It Follows_ provides aren't always of the predictable variety. That's exciting. The hazy, moody atmosphere is another plus, blending elements of several distinct eras to create a familiar, but also oddly skewed, backdrop that amplifies the film's persistent sense of the unnatural.

It's a story that doesn't try to do too much, because it doesn't need to. Remaining laser-focused on exploring that one central idea, plus the reactions of a refined, condensed cast of characters, is more than enough. Why complicate things?