Prepare to be horrified, worried, relieved, astounded

NEW YORK - Billy: "You shouldn't laugh at people's misfortunes."

Bartley: "Why?"

A good question, asked by everything Martin McDonough writes. The Irish wizard of the hilariously horrific (or horrifically hilarious), McDonough's more recent work is the play

The Pillowman

and the film

In Bruges

. Druid Theatre's flawless production of his 1997

The Cripple of Inishmaan

, directed by Garry Hynes, has transferred intact to the Atlantic Theater for a brief New York run following its United Kingdom tour.

The Cripple of Inishmaan

takes place on one of the tiny islands off the west coast of Ireland. The strength of the cast, the dead-right detail of the unadorned set, and the extraordinary lighting create an atmosphere so thick, so evocative, that watching the play feels more like being a traveler than a theatergoer; for 21/2 hours you feel as though you are in that village, in 1934.

It is a cruel, absurd, heartbreaking and brave place where profound loneliness makes people stare at cows and speak to stones and try but fail to drink themselves dead for 65 years. "Has the eggman come?" "He has, but he had no eggs."

The local daily news - delivered by gossipmonger Johnnypateenmike (the superbly prissy-slimy David Pearse) - is that a Hollywood crew has come to a neighboring island and needs extras to make a movie. This will turn out to be Robert Flaherty's classic documentary

Man of Aran

, supposedly about the "daily life" of people like these, suggesting but not belaboring the complex joke of authenticity and Irish quaintness.

Billy, the teenage cripple of the title (a deeply moving Aaron Monaghan, who not only distorts his body but creates a painful wheezing whistle when he breathes) wants this chance to escape his grim life of mockery and humiliation.

Orphaned as an infant by parents who abandoned him via suicide, he is sick and sad and longing for love. He persuades Babbybobby (Andrew Connolly) to row him across to the filming, along with slutty, mean Helen (Kerry Condon) who pegs eggs at everyone (thus the eggman's lack) and her brother Bartley (Laurence Kinlan). Billy's eccentric aunties (two splendid performances by Marie Mullen and Dearbhla Molloy) fret when he disappears without a word for four months.

The plot is complicated and twisty: We are betrayed as often as the characters are, by rumor that turns out to be misinformation, confessions that turn out to be ploys. First we're worried, then horrified, then relieved, then shocked, then astounded.

The actors never allow these characters to descend into caricatures, and speak the language with accents so authentic and phrasing so tasty that they can make a meal of a line.

Through Feb. 1 at Atlantic Theater, 336 W. 20th St., New York. Tickets $65. Information: 212-279-4200 or ticketcentral.com.