The polar opposite of a comfort watch, Ari Aster’s debut is impossible to look away from

The “creepy thriller” subgenre uses a different playbook from most horror movies. Horror often defers to the easy shock of a killer on the loose or a supernatural threat, but a creep-fest mines horror from everyday moments and mundane scares, then exaggerates them to extreme lengths to create an uncomfortable story.

Within this tense genre, a 2018 movie is a masterclass in the slow boil of family horror. It’s a truly unsettling thriller that launched a trend — and a career.

Ari Aster’s directorial feature debut, Hereditary, shouldn’t have worked as well as it did. The premise is simple: After the loss of her mother, a woman finds her life and family eerily changed. The supernatural appears to be lurking, but what makes the film so gripping and intriguing is the human element Aster is so skilled at bringing to life.

Annie (a delightfully unhinged Toni Collette) is a miniaturist who crafts complex dollhouses for a living. Her life feels like the basis of a typical downer family drama, but then tragedy strikes.

Her son, Peter (Alex Wolff), is invited to a party and brings his sister Charlie (Milly Shapiro). There, Charlie accidentally triggers her nut allergy and goes into anaphylactic shock. On the drive to the hospital, Charlie leans out the window to gasp for air, only to hit her head against a telephone pole, decapitating her.

A distraught Annie blames her son for her daughter’s death and is driven to extreme lengths to determine why her life is crumbling. The truth, which she finds in her mother’s belongings, is more disturbing than she — and the viewer — could have imagined.

The plot seeps into the production. Much of the family’s house was filmed on a soundstage, allowing scenes to be shot with the walls sliced off, like a dollhouse. The trick reflects both Annie’s profession and her mother’s manipulation of her from beyond the grave.

As the name suggests, Hereditary focuses on what we inherit from our family: Their flaws, their obsessions, their neuroses. Even when you go out of your way to change your life and break the cycle established by your parents, remnants remain inside you — and are passed down to your children.

Much like Aster’s follow-up, Midsommar, Hereditary also deals with the harsh reality of familial loss. It’s an emotion that’s difficult to show on film, not only because of how abstract the feeling is, but also because of how hard it is to watch. Thinking about the loss of people close to you isn’t exactly a fun fantasy, but Aster shows it in blinding light. His disturbing images should drive viewers away, and yet, because of the careful cinematography at work, the whole affair almost makes logical sense.

Hereditary is psychologically harrowing, but it’s also just a well-crafted film. A balance of social fears, familial fears, cultural fears, and good old-fashioned satanic panic creates a world where spontaneous combustion is one of the tamer shocks. It’s an unsettling experience that will linger with you long after the credits have scrolled by.

Hereditary is streaming on HBO Max.