Considerable advance buzz heralded the New York premiere of Enda Walsh’s “The Walworth Farce,” an Irish import from Galway’s estimable Druid Theatre Company, now at St. Ann’s Warehouse in DUMBO, and Mikel Murfi’s well-oiled production of this dark Irish brew lives up to the hype. “The Walworth Farce” is as brilliant an original as you are likely to see in the theater this year.

The play takes place simultaneously in three cross-sectioned rooms of a squalid London flat, all with stained wallpaper and ratty furniture. As it opens, Dinny (Denis Conway), a middle-aged dad, is preening and doing calisthenics in the den. In the cramped bedroom, his grown son Blake (Garrett Lombard) is ironing a skirt. Meanwhile Sean (Tadhg Murphy), his other son, unpacks groceries in the kitchen.

Suddenly, they spring into action — dashing around the apartment, sputtering the rapid-fire lines of some overly complicated play. It’s an Irish amateur version of “The Three Stooges,” a bunch of exaggerated vaudeville skits strung together. The boys change characters on the fly, donning and dropping wigs, costumes, and accents. Blake plays all the female roles. And Dinny, who rules the roost with an iron fist, plays only himself.

It would be unsporting to give away too many of Mr. Walsh’s plot twists, so suffice it to say that the play-within-the-play dramatizes the events of the day 20 long years ago when Dinny (and subsequently, his young sons) left their beloved home in Cork for a grim life in a public housing complex in London. Dinny and his sons perform this amateur theatrical every day, without an audience, in their moldering apartment, vying to outdo each other and claim temporary possession of the “acting trophy” Dinny keeps on a high shelf.

The actors have ordinary, plain faces, the flat (designed by Sabine Dargent) is an eyesore, and both the writing and acting are (appropriately) crude. The props are homemade: small coffins made out of old bits of cardboard, wads of bills poached from the Monopoly set, a roast chicken bought at the local chain supermarket. Yet the proceedings have a sort of cheap razzle-dazzle, a threadbare showmanship that only underscores how pathetic these men are.

The machinery, however, is about to break down. The trouble begins when Sean, the only family member who ever leaves the flat, brings home the wrong shopping bag from the supermarket. By the end of the first act, the unthinkable has happened: Someone’s ringing the doorbell. It’s Hayley (Mercy Ojelade), a young supermarket checkout girl, the sort of generous spirit who has decided to bring Sean the correct grocery bag on her lunch break. The introduction of an innocent like Hayley into the family’s dark, dysfunctional world ratchets the tension up several notches. Suddenly we see these men through her eyes: Sean, the cringing, tortured son who can barely acknowledge his desire to break free; Blake, who’s been playing female characters for so long that he’s begun to identify with them; Dinny, the tyrant who uses the family “story” to trap his grown sons in a cycle of interdependence and feed his own needs.

It’s the genius of Mr. Walsh’s writing that Dinny’s play-within-a-play resonates as the consummate example of something many a needy parent imposes on grown children: a demand for absolute loyalty to the family on certain occasions, punishable by shunning. “We’re making a routine that keeps our family safe!” Dinny declares at one point. Yet it’s clear that the person kept safe by the routine is, in fact, Dinny.

Mr. Murfi finesses the abrupt changes of tone with unerring instinct, aided by a formidable cast. Ms. Ojelade injects the perfect note of sweet, unsettling normalcy; her budding friendship with Mr. Murphy’s emotionally crippled Sean has real potency. Mr. Lombard’s unfussy portrayal of Blake is masterful; we empathize deeply with his fascination with the feminine. And Mr. Conway’s highly combustible Dinny is a force that anchors the play. Leaning back, thrusting his pelvis out, exuding jocular charm, he’s the epitome of a man who needs to dominate.

Make no mistake: “The Walworth Farce” is a strenuous evening, zigzagging through a pitch-black family history, trapping a lamb in a lion’s den, and teasing the brain with its digressions and meta-commentary. (There are layers within layers in Mr. Walsh’s construction — not least of which is some meditation on the need for theater itself, and the effects of reciting the same lines, night after night.) Yet the audience’s exertion is repaid in full. It is exhilarating to hang on for dear life on a ride through Mr. Walsh’s bold, original imagination.

Until May 4 (38 Water St., DUMBO, Brooklyn, 718-254-8779).