On paper, writer/director Ari Aster's feature debut Hereditary has all the trappings of your standard psych-horror thriller. By watching the trailers, you've probably got a pretty solid idea of what you think the movie is about forming in your head: dead grandma, creepy kid, mentally unstable mom -- a laundry list of tried-and-true horror tropes all laid out in a neat little row.

Here's the thing: Hereditary isn't actually that movie. It's something much more interesting.

Hereditary centers on the Grahams, a suburban family consisting of mother Annie (Toni Collette), a woman with the somewhat eccentric career of miniature sculpting; father Steve (Gabriel Bryne), who is really just doing his best; and two kids: Peter (Alex Wolff), an exceedingly normal high school student, and Charlie (Milly Shapiro), an introverted 13-year-old who was her late grandmother's favorite. We join them immediately in the wake of the grandma's funeral where we learn that she was a closed-off, cold, and secretive woman with whom Annie was very nearly estranged from after a cavalcade of tragedies and family drama drove a wedge between them early on.

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The setup, admittedly, doesn't feel all that new. The first act is the same slow-burning tension that you might find in a horror-melodrama classic like Rosemary's Baby where the supernatural stuff is largely relegated to the background, as we stick close to group of people trying and (predictably) failing to process their grief for a woman they barely knew. Hereditary makes a conscious effort to effectively lull it's audience into that false sense of security by playing up familiar moments -- is Annie just losing her mind with guilt and grief? Was the grandmother just a normal, albeit withdrawn woman? For 40-or-so minutes, you'll find yourself bracing for those eventual reveals.

But, just as you start to really fall into the comfortable rhythm of the formula being touted, things take a sharp turn off the path. And then it keeps turning, and turning, and turning until it ends in a climax that, in retrospect feels both inevitable and completely out-of-left-field.

It's in this subversion of genre expectations that Hereditary really finds its strength. Collette's career-defining fragility and desperation as Annie -- a mom who in any other horror movie would have been abusive, unstable, villainous or all three -- at once shines with such raw emotion that even as things start to truly come off the rails, the stakes still feel grounded and real. The result is a terrifying downward spiral in which every part of the mystery surrounding the Graham family comes to light in an unexpected and absolutely dreadful way -- not only because the events themselves are completely horrifying, but because you really can't help but root for the Grahams to make it through this, even as that idea becomes increasingly less likely as things continue on.

In terms of thrills-per-minute, Hereditary's specific brand of horror could be best described as restrained. It withholds most major gross-out moments and easy jump scares in favor of letting subtle, encroaching dread sit and linger in the background. Sound design becomes a key part in ramping up the terror with ambient noises -- tongue clicks, floor creaks, feet thudding down halls -- bolstered by an almost Trent Reznor-flavored soundtrack of dissonant electronic humming, crackling and thumping.

That's not to say there aren't a few classic jump scare moments to go around, but by holding them on a tight leash, Hereditary is able to cultivate a world in which everything feels like a potential threat, even in broad daylight. More often than not these threats aren't acted upon, which in a way, almost makes the suffocating anxiety of the situation worse. This is less a "throw your popcorn in the air and scream" fright fest like this year's critically acclaimed A Quiet Place, and more a "sink down in your chair and mumble, 'oh god, oh no,'" spiral; a car crash you can't look away from.

If Hereditary stumbles at all, it's in its length. It's lingering, meandering efforts to promote each and every one of its genre bluffs and red herrings could start to feel tedious to anyone who isn't already bought and sold into the thrill ride. At more than two hours in run time, it's not hard not hard to look back and see bits of fat that could have been trimmed. Still, being slightly too long or too overwrought is hardly a deal breaker.

Hereditary is not one that horror and genre fans will want to miss.

Hereditary, directed by Ari Aster, is in theaters on June 8.