NEW YORK (OSV News) -- Mrs. Portnoy step aside, there's a new Jewish-mother-from-hell in town. And she's the reason "Beau Is Afraid" (A24).

Billed as a dark comedy, writer-director Ari Aster's deep dive into paranoia is instead a nightmarish, three-hour-long odyssey through a landscape of mental misery. While Aster's obvious artistic intent creates a sufficient context to prevent his film from being entirely unacceptable, moreover, it's nonetheless chockablock with challenging content.

Viewers unwise enough to patronize the movie will find themselves trapped in the disturbed mind of timid loner Beau Wassermann (Joaquin Phoenix). Beau's tortured relationship with his mom, Mona (Patti LuPone), inspires and overshadows a series of what are presented as bizarre adventures for him but some of which, at least, are really hallucinations.

Though Mona is a super-successful CEO, Beau inexplicably lives in an exaggeratedly dystopian urban neighborhood where a naked madman randomly stabs passersby and the body of a suicidal roof jumper is left to rot where it fell. Beau himself eventually becomes a victim of this environment when, shot at by a rogue cop, he runs into the street and is hit by a van.

He wakes up in the home of a duo of strangers: avuncular, indefatigably cheerful surgeon Roger (Nathan Lane) and his breezy wife, Grace (Amy Ryan). They initially nurture Beau as he recuperates. But, after a weird incident involving the couple's daughter, Toni (Kylie Rogers), Grace turns on Beau.

Roger and Grace also have given shelter to Jeeves (Denis Ménochet), a mentally ill veteran who was a comrade of their fallen son and now lives in an RV on their property. Grace tells Jeeves to kill Beau, forcing the latter to flee into a nearby wood.

There, a play staged by a group of wandering actors and an animated sequence in which Beau is the protagonist explore possible alternative lives he might have pursued. All these interludes, from the road accident onward, however, are unwanted detours thwarting Beau's effort to travel back to his childhood home -- where Mona may be awaiting him or may be lying dead.

Erotic inhibition is one of the script's major themes. We're shown flashbacks to teen Beau's (Armen Nahapetian) one shot at romance with fellow cruise passenger Elaine (Julia Antonelli). But Mona has told Beau that his father died in the act of conceiving him and that Beau suffers from the same heart complaint that did Dad in, thus making his own desires a source of terror.

Beau eventually experiences a barrier-breaking encounter in this respect. While the treatment of this event is certainly explicit, it registers as more pathetic than exploitative. And, as with everything else in the movie, it's uncertain whether we're dealing with reality or merely Beau's warped imagination.

Aster's work is undoubtedly original and -- for better or worse -- entirely unfettered. Yet what his movie ultimately means is anyone's guess. The upshot, despite a dedicated performance from Phoenix, is an emotionally burdensome, intellectually frustrating enigma.

The film contains graphic sexual activity, full nudity, gory violence, gruesome images, drug use, frequent mild oaths, pervasive rough language and much crude and crass talk. The OSV News classification is L -- limited adult audience, films whose problematic content many adults would find troubling. The Motion Picture Association rating is R -- restricted. Under 17 requires accompanying parent or adult guardian.- - -John Mulderig is media reviewer for OSV News. Follow him on Twitter @JohnMulderig1.- - -CAPSULE REVIEW"Beau Is Afraid" (A24)Nightmarish dark comedy traps viewers in the disturbed mind of a timid loner (Joaquin Phoenix) whose tortured relationship with his mother (Patti LuPone) inspires and overshadows a series of what are presented as bizarre adventures for him but some of which, at least, are really hallucinations. After being hit by a van, he recuperates in the home of a surgeon (Nathan Lane) and his wife (Amy Ryan). But the latter turns against him and tells a mentally ill veteran (Denis Ménochet) who lives on the couple's property to kill him. He flees into a nearby wood where a play staged by a group of wandering actors and an animated sequence in which he's the protagonist explore possible alternative lives he might have pursued. Writer-director Ari Aster's deep dive into paranoia is undoubtedly original, though what it ultimately means is anyone's guess. Erotic inhibition is one of the script's major themes. Yet the treatment of an eventual barrier-breaking encounter, while certainly explicit, is more pathetic than exploitative. Graphic sexual activity, full nudity, gory violence, gruesome images, drug use, frequent mild oaths, pervasive rough language, much crude and crass talk. The OSV News classification is L -- limited adult audience, films whose problematic content many adults would find troubling. The Motion Picture Association rating is R -- restricted. Under 17 requires accompanying parent or adult guardian. - - -CLASSIFICATION"Beau Is Afraid" (A24) -- OSV News classification, L -- limited adult audience, films whose problematic content many adults would find troubling. Motion Picture Association rating, R -- restricted. Under 17 requires accompanying parent or adult guardian.