Ari Aster’s “Hereditary” is undoubtedly one of the scariest movies of the century, if not of all time. While Aster is at maestro-level in his feature debut, it’s truly Toni Collette’s gut-wrenching, bereaved, terrifyingly unhinged performance that elevates “Hereditary” above its haunted house ilk. Collette is so good here — truthfully, unequivocally — that she doesn’t just deserve mention among the greats of horror, but the cinematic greats period. It’s a transcendent, bone-chilling performance.

Collette’s best moment comes in the perennially memed second act dinner. As Collette’s Annie sits down to dinner with her husband (Gabriel Byrne) and son, Peter (Alex Wolff), the tension between her and Peter is sever-a-head-with-a-telephone-pole palpable. As they argue, both grappling with grief in their own way, Collette explodes, accosting Peter for his selfishness while blaming him for the death of her youngest daughter, Charlie (Milly Shapiro). It’s a tour-de-force, sure, but it’s also the movie’s scariest moment. In a film abounding with sinister cults and sundry beheadings, that’s saying something.