Writer/director Ari Aster has forged his reputation with the double whammy of Hereditaryand Midsommar,teen girls abused video sex two films that are both harrowingly horrifying yet slyly funny. Fans who've relished the nightmare-scorching visuals and deeply twisted finales of Aster's work thus far might expect something similar in his latest. Good news for fans: Beau Is Afraidis peppered with jaw-dropping horrors and jokes so dark you might laugh or scream.

Yet, this epic — which Aster describes as a "Jewish Lord of the Rings" — sets its own course, trekking not only far from horror conventions, but from movie conventions as well. The result is a film that is shocking, immersive and so emotionally raw that it's essentially a three-hour-long panic attack as cinema. 

Proceed with caution. 

What is Beau Is Afraid about? 

In its simplest form, Beau Is Afraid is about a fearful loser trying to make his way to his overbearing mother's house. Of course, Aster complicates this journey with a cascade of what-ifs, chasing down the worst-case scenario at every opportunity. What's the worst that could happen if you lost your keys? If you missed your flight? If you disappointed your mother? 

If you've ever been tormented by a similarly relentless internal chorus, you'll relate to Beau's dilemma. He is frozen by the possibilities until fate — like a relentless bully — pushes him not to act, but to react. He is forced to leave the relative safety of his grubby apartment for urban streets that are booming with noise and chaos, littered with a rotting corpse, a half-naked dancer, and a fully nude serial stabber.

Violence will push him farther and farther out of his comfort zone to settings disparate and not always obviously perilous. He'll find himself awash in the eerie comforts of a posh suburban family, amid a wandering theater troupe, adrift in an animated fantasy, all before finding his way to a mansion whose cold architecture warns us that it is — in a sense — a prison. And then Beau Is Afraid goes even farther, chucking audiences into a nightmarish terrain we could never predict. And yet you may find yourself smiling like a madman all the way. 

Joaquin Phoenix leads a preposterously incredible cast. 

Academy Award-winner Joaquin Phoenix stars as Beau, portraying the timid man behind a scruffy stubble; wispy, retreating gray hair; and an expression that glides from dumbfounded to aggrieved to horrified in the blink of an eye. This is an intensely demanding performance that thrusts the heralded actor through mind-snapping scenarios, one after another, as well as pushing him physically; a run to the bodega is treated like an obstacle course with life-or-death stakes. Even awkward social interactions might result in an abrupt attack, and so Joaquin plays Beau like a battered animal, eternally skittish. His fear is constant and twitches at contagious, urging the audience to generously share in his anxiety through each hellish turn. 

Beau Is Afraidis structured less like a film and more like a novel, with each chapter chucking Beau into a new setting. Production designer Fiona Crombie masterfully distinguishes each world from the next, so that it might seem as if Beau has stumbled out of his movie, which begins in a metropolis gone feral, into something softer and more fantastical. These spaces are occupied by a ridiculous stacking of stars, which bring distinctive and dynamic charges to each chapter. 

Paired as plucky parents, Amy Ryan and Nathan Lane bring a brightness so bouncy that simple salutations play as punchlines. As their daughter Toni, Kylie Rogers's growling menace offers a ferocious parody of teen angst. In flashbacks to Beau's childhood, Zoe Lister-Jones plays a younger version of his mother, Mona, with a snarling sharpness, while a wide-eyed Armen Nahapetian captures teen Beau's mix of wonder and terror. Celebrated character actors Stephen McKinley Henderson (Dune, Fences) and Richard Kind give wickedly funny performances as a therapist and lawyer, respectively. Parker Posey is perfectly cast for a third-act turn that is darkly, deliriously outrageous, and sure to psychologically scar '90s kids who grew up in awe of her. 

Finally, Patti LuPone stars as Beau's awaiting mother. And here I digress to note that Aster has said Beau Is Afraidwas first drafted ten years ago —before he made Hereditary and Midsommar. In LuPone's Mona, you can see clear ties to Hereditary's harried mother and the tortured bond she shares with her son. But here, the mother is not the hero or the anti-hero; she is the merciless antagonist.

LuPone, a living legend of the Broadway stage who has defined diva roles again and again, makes a feast of Mona. She stalks into the room like a grand dame of film noir, or perhaps the sultry witch of an erotic '80s midnight movie. She spits accusations and insults and condemnations with such intensity that you might feel compelled to apologize to your own mother for being a damn burden. But most thrilling, LuPone is given a monologue that makes Toni Collette's nerve-shredding "I am your mother" speech feel a tad tame. It's exhilarating to watch this icon sink her teeth into this speech, and it is absolutely spine-chilling to take it all in. 

• 'Beau Is Afraid' exclusive clip takes a deeper look into this bizarre film
• 'Beau is Afraid' trailer: Ari Aster and Joaquin Phoenix serve up surrealism
• 'Midsommar' is a beautiful nightmare that reinvents what horror can be
• The best comedies streaming on Netflix right now
• The best Mother's Day gift ideas (for every kind of mum)

Beau Is Afraid is a cinematic dare. 

As he has in his first two films, Aster has paired powerful performers with a script that plunges into the surreal and the psychological. His movies feel like a dare, challenging audiences with visuals of beautiful bodies destroyed by self-loathing, audio that creeps under your skin, and plot twists that feel wrong yet oh, so terribly right. 

Beau Is Afraidis a challenge in that its exploration of terror doesn't allow you the reprieve typically provided in horror. There are no jump scares to give you the release of a scream. The film instead operates on a wicked sense of whimsy, propelling its protagonist forward without much respite, despite flights of fantasy. So too are we pushed to the brink, wallowing in uncertainty and anxiety, on the edge of our seats over what might come next. 

Ultimately, Beau Is Afraidis Ari Aster's answer to The Truman Show, a film in which an everyman fears that everyone around him knows something he doesn't and is out to get him. However, instead of cloaking that horrific scenario in the winsomeness of a 1950s sitcom, Aster propels us into modern landscapes, tweaked to a place of parody but not to the point of unfamiliarity. There are visuals gags, gross and urbane, found in graffiti, band posters, and the promotional art outside a curious strip club. In the final act, there is a music cue at once perfect and utterly absurd, which led surprise audiences to squeal. This is the world we know at its very worst...and at its most chaotically fun.

Still, I can't promise you'll enjoy Beau is Afraid. I can promise it'll fuck you up. 

Beau is Afraidopens in NY/LA on April 14, then nationwide on April 21.