At first impression, Hereditary seems to be an upsetting horror movie that tackles grief, motherhood and the supernatural, but upon further reflection, it becomes clear that there is more going on. Portraying mental illness in a horror film can be difficult to do well as it is all too easy to make a mockery of real people’s experiences. Hereditary walks the fine line of showing the effects of illness without descending into parody. That it manages to do so while being a damn good horror film is a welcome feat in a genre that is so often considered to be one dimensional due to the plethora of predictable movies released every year.

Annie Graham (Toni Collette) is a miniatures artist whose difficult mother has just died after a slow and painful illness. While Annie struggles to process the grief she may or may not be feeling due to the incredibly complex relationship with her mom, she and her children begin to be plagued with nightmares, strange visions and paranormal events in their house. Thirteen-year-old Charlie (Milly Shapiro), her deceased grandmother’s favorite, has always been different and after the death, she begins to withdraw from her family and into her own world of drawings and collage. Peter (Alex Wolff), the oldest child, seems to be fine, but as things progress his dreams take on a vivid and dangerous tone and he isn’t quite sure whether or not they really were dreams.  In an attempt to deal with her tenuous grief without worrying her family, Annie attends an anonymous support group and finds herself spilling out the details of her life and her maternal relationship but finds no peace in doing so.

A few weeks later, Annie encourages Peter to bring Charlie with him to a high school party, but while they are there a terrible event occurs that leaves Annie wretched with grief and on the edge of sanity. Annie returns to the support group and meets Joan, who has suffered her own tragedy and the two women form a fragile bond over their losses. When Joan offers to help in an unconventional way, Annie impulsively takes her up on it, unknowingly putting her family at great risk and may end up being their destruction. While so much of the story sounds like a fairly typical horror movie, it is the rich detail that director Avi Aster weaves throughout its runtime that makes the film so powerful

While Hereditary isn’t a traditional horror film, it uses the trappings of one like a consummate professional. There are jump scares, floaty lights and gruesome effects, but they are all secondary to the creeping dread that suffuses the events unfolding on the screen. Hereditary is a slow burn that isn’t afraid to allow the audience to see what’s coming, but even though it may be obvious what is about to happen, it’s impossible to look away, lest the secret to what is really going on lie within those scenes. As things grow more dire it becomes impossible to tell the difference between reality and a grotesque nightmare for both the characters and the viewer. By the end it becomes clear that when it comes down to it, it doesn’t matter whether there really are ghosts or demons or mysterious cults at work, for Annie, Charlie and Peter these events are as real and as dangerous as anything else in their world.

The entirety of the cast of Hereditary is fantastic, but the three women at its center are riveting to watch, most of all Toni Collette. With her trademark intensity, she elevates the role beyond the already great material into something that keeps the viewer thinking long after they have left the theater. She throws herself into every scene with a physicality that demands a reaction. As Charlie, Milly Shapiro owns every bit of creepiness she is propelling at the screen and despite her eventual status as a victim, she feels like an otherworldly being. Ann Dowd recently showed off her skills at being a villain as the cruel and totalitarian Aunt Lydia in Handmaids Tale, but she sheds every vestige of that in Hereditary as a seemingly sweet and helpful friend to Annie.

Hereditary can be difficult to watch as it taps into fears and pain that is not often shown with such provocative imagery and it is not for the faint of heart or those who are easily affected by such things. But for those who are willing and able to take this ride, it is likely to offer hours of discussion among friends and maybe even a few nightmares of your own.