A Behanding in Spokane, Martin McDonagh’s first American-based play, turns out to be a subtle, brutally funny indictment of America. So funny and so brutal, in fact, that multiple theatergoers left their seats during the 90-minute show to storm out of the theater.

Having spent the last 47 years searching for his left hand, which a gang of hillbillies (allegedly) held on a train track until a passing train severed it, Carmichael (Christopher Walken) thinks he may have finally found it while staying in a seedy motel, thanks to two dim-witted pot dealers. Unfortunately, in a page straight out of Flannery O’Connor (who knew a thing or two about the dark side of Americans), Marilyn (Zoe Kazan) and her boyfriend Toby (Anthony Mackie) swiped the hand of an Aborigine from a museum in a ludicrous attempt to con Carmichael. Needless to say, a man hauling around a gun and a suspiciously heavy suitcase is not amused to find himself the target of an attempted grift. Things are only complicated by receptionist Mervyn (a superlative Sam Rockwell), who has waited his whole life to be a hero, even fantasizing about a high school shooting that would let him courageously save lives. And Mervyn, too, has a bone to pick with Toby.

McDonagh only allows 9/11 to slip by, but the rest of America’s obsessions are all neatly displayed and then briskly dispensed with, especially our collective obsession with race. Judging from the two matinee ladies in front of me, the repeated use of “white cracker” and the n-word didn’t go over well with some of the more staid theatergoers, but that’s all for the better. Broadway has gone too long without a play this vicious and mean-spirited; the time has come to remember that there’s more to high-priced New York theater than revivals of shows that every high school theater department has been staging for the last half century (or shows that return to Broadway every decade or so). McDonagh, who also wrote the unsettling The Lieutenant of Inishmore and The Pillowman, knows a great deal about unsettling audiences, and he proves it all over again here.

Still, it would have been nice if the Irish McDonagh, who knows our flaws so well, also knew how to write dialogue for American characters. Toby, who proves himself far from a wordsmith, uses the phrase “rang,” instead of “called,” something that immediately marks him as not quite American. But both Mackie and Kazan are so stylized—he doing a riff on Richard Prior’s jive talk and she aiming for ditzy but coming closer to slack-jawed yockel—that the occasional mistakes in vernacular hardly register. Walken, who knows a thing or two about stylized performances himself, and Rockwell are more accomplished. Rockwell, in particular, gives the kind of weasly, oily performance that prevents Mervyn from becoming just a clumsy oaf. And Walken’s off-kilter delivery has rarely been utilized so well as the murderously angry Carmichael, searching, like the worst Americans, for something that he might very well have thrown away himself.

>A Behanding in Spokane

Through June 6, Schoenfeld Theatre, 236 W. 45th St. (betw. 8th Ave & B’way), 212-239-6200; $61.50–$116.50.