When the family matriarch dies after a protracted, painful battle with dementia and cancer, her surviving family are forced to deal with her difficult legacy head on, the fallout from which threatens to consume both generations of her relatives. Spare a thought for her poor son-in-law, forced to watch helplessly as his family crumbles in the wake of this woman's sinister machinations.

And that's all I'll say about that. Yes, it's another 'just go and watch the movie' review, as Hereditary is best watched with as few preconceptions as possible. Avoid the trailers, skip the reviews, stay away from spoilers, just get Hereditary into your life as soon as possible. A film is more than just the sum of its plot points, but some of those delivered here are so life-shattering that they deserve to be experienced first-hand wherever possible.

At first glance, it covers similar ground to The Babadook,  A Quiet Place and particularly The VVitch; a family in crisis, tearing each other apart with grief, guilt and unspoken blame. This one, however, makes A Quiet Place look positively schmaltzy by comparison (which, c'mon, it is a bit). Mom's a powder-keg, dad's a wimp, their son's a stoner loser and their daughter is a weirdo serial-killer in the making, each of them tainted in some way by grandma's brand. Its subtext is laid on thick, a grim portrait of the baggage we inherit from our relatives, no matter how much we may try to learn and better ourselves.

But, like its predecessors, Hereditary is also a film about scary supernatural things happening to (relatively) average people, and that's what people are really tuning in for. And the first act absolutely delivers on those goods, perhaps the strongest setup to a horror film since The Exorcist or The Shining. Were it able to maintain that ferocity on its own terms, we might have an all-timer on our hands.

Sadly, it can't, giving into over-explanation and exposition. The nature of its evil feels shoehorned in, as though director Ari Aster found his story and subtext first, then had to work backwards to explain it: it doesn't feel quite organic, like a more conventional ghost story wedged into an abstract arthouse flick. The scares, too, once we're deeply ensconced in the film's second half, are at odds with the atmosphere of the first. Contrast this with The Babadook and The VVitch, both of which balance theme and palpable menace expertly.

And then it's into the endgame, which delivers last act thrills, spills and shocks so effectively that its slight dip in the middle is almost forgotten. It's a fairly traditional supernatural showdown dialled up as far as it will go, like a Sinister or Insidious movie on bath salts. Again, it doesn't quite gel with the brilliance of that first half hour or so, but it is a different kind of brilliant, delivering some of the most unsettling imagery and action in years.

While this is a film at odds with itself, that's not to say that it's inconsistent. The performances are excellent across the board, and while Toni Collette understandably emerges as the MVP (someone get that lady an Oscar), Alex Wolff is almost as impressive, marking himself as more than Just That Kid From Jumanji. Aster's script asks a lot of them, emotional high-stakes melodrama with a sneaky undercurrent of black comedy and the most traumatic family in-fighting since Mother!

By cannily cutting to and from Annie Graham's intricately depicted miniatures, Aster establishes an uncomfortable sense of otherness and artificiality; a world in which everything is just ever so slightly off-kilter. Especially Mom.

Had it maintained that obtuse opacity, Hereditary might have become a modern classic. As it stands, it makes a good run for it: the sound design, mood and cinematography are some of the best I've ever encountered in a horror film. It's upsetting, unsettling and unusual, and an astonishing debut. It's too absurd to be truly scary, but its horrors are real. Hereditary gets under the skin, and it stays there.