Even the most adventurous moviegoer could be forgiven for steering clear of Killer Joe, William Friedkin’s brazen new adaptation of a 1993 play by Tracy Letts. One of the first things you see in the film, a grimly comic thriller about deadly doings at a Dallas trailer park, is a shot of Gina Gershon naked from the waist down. One of the last things you see is Matthew McConaughey smashing in Emile Hirsch’s face with what looks to be a can of pumpkin pie filling. In between, there is murder, arson, and an extended, altogether indescribable bit of insanity involving a fried-chicken drumstick. (I’d dare you to use your imagination except that you’d never come up with anything nearly as depraved as what actually happens.) The movie, which has been slapped with an NC-17 rating, starts out deliciously macabre but steadily devolves into camp: its Hollywood stars end up drenched in blood, shouting and simpering and pretending to be white trash. No one, least of all Gershon—who suffers the worst of the drumstick assault—survives with his or her dignity intact.

Yet Killer Joe, which opens next month in limited release, might also be the most intriguing film I’ve seen this year, partly because it pushes the Southern gothic genre into whacked-out, Texas-flavored terrain but mostly because it shows us one of our favorite sons working overtime to obliterate his reputation as a good-time guy. Indeed, casting the perpetually sunshiny McConaughey to play a crooked Dallas cop who moonlights as a murderer is one of many risks that Friedkin and Letts (who wrote the screenplay adaptation) have taken—a risk that doesn’t always pay off. But even when the star’s performance teeters, and even if the material makes you wince, you don’t want to look away for fear of missing whatever weird thing might happen next.

Originally written before Letts’s more celebrated works, Bug (1996) and August: Osage County (2007), Killer Joe introduces us to Chris Smith (Hirsch), a ne’er-do-well who pays a visit to his trailer-living father, Ansel (Thomas Haden Church), and stepmother, Sharla (Gershon), with what he believes to be a foolproof plan to pay off his underworld debts. He will hire a man known as “Killer Joe” Cooper (McConaughey) to murder his mother. Her $50,000 life insurance policy will then be paid to Chris’s younger sister, Dottie (Juno Temple). After paying off Joe, the four of them—Chris, Ansel, Sharla, and Dottie—will split the proceeds. This is a classic noir setup served with a hearty helping of family dysfunction, a kind of unwieldy mash-up of Cormac McCarthy, Flannery O’Connor, and Sam Shepard. Letts, who was born in Oklahoma and lived in Dallas after high school, has an ear for Southern hypocrisies and stupidities, and he both mercilessly anatomizes these loutish figures and displays an oddball affection for them. For his part, Friedkin (best known for The Exorcist and The French Connection and who also directed the 2006 film version of Bug) conjures up a desolate landscape where snarling pit bulls terrorize mobile home parks and dirty deals go down in boarded-up pool halls. The images don’t quite look like Dallas (the film was mostly shot in New Orleans), but they still seem to capture a certain rotted-out, mercenary quality of the city.

And then there’s McConaughey, who enters wearing aviator shades and a black cowboy hat—and, at least for the next hour or so, delivers the wittiest, most electric performance of his career. Joe scoffs when Chris proposes paying him for the hit only after the insurance money has been collected—until, that is, his eyes alight upon Dottie, whom he agrees to accept as his “retainer.” With a voice lower and 
less drawly than usual and an expression that alternates between a smirk and a scowl, McConaughey makes for a wonderfully magnetic perv. (Is this what his Dazed and Confused character would be like if he’d become a contract killer?) Joe sweet-talks Dottie into bed, and he is soon spending evenings in Ansel’s trailer. That the actor never oversells any of this, portraying Joe as a matter-of-fact businessman utterly sincere in his affection for an innocent girl, makes the scenario all the more icky and that much more plausible.

I wish I could report that McConaughey finds a way to deepen and transform his character into a true movie monster. The material certainly demands a towering, Anton Chigurh–like figure of terror, someone who can lend gravity to the cartoonish gruesomeness of the final act. But McConaughey doesn’t entirely let go of the narcissism that has long characterized his work, nor does he demonstrate the chops for such heavy lifting. Midway through the film, Joe parades naked through the trailer as the other characters look on in puzzlement. The scene is supposed to startle the audience into laughter, and perhaps underline Joe’s egomania, but mostly it just throws you out of the drama. You’re reminded that McConaughey is a little too pretty and gym-toned—a little too spiritually soft—to play someone so animalistic. Toward the end of the picture, as the characters all converge and assorted double- and triple-crossings are exposed, his performance unravels and the movie along with it. Maybe the cause was a lost one from the start—I’m not sure any actor could make the drumstick bit believable. But when McConaughey starts screaming and pummeling his co-stars and making orgasm faces, there’s no serious sense of menace. When you’re playing someone who comes unglued (think Daniel Day-Lewis in There Will Be Blood or Robert De Niro in Raging Bull), you shouldn’t look, as McConaughey does, like you’re having a good time.

That said, I’ll take a stunted performance like this one over the kind of happy-go-lucky preening we usually get from McConaughey, and between this and his turn in last year’s enjoyable The Lincoln Lawyer (as well as in this month’s Bernie; see page 138), I’m increasingly of the mind that there might yet be a way to use the actor’s charm against type, the way Alfred Hitchcock used Jimmy Stewart in Vertigo and Rear Window or the way Anthony Minghella used Matt Damon in The Talented Mr. Ripley (see “Keep Your Shirt On”). As for Killer Joe, sure, it’s grisly and half-senseless, and Friedkin’s camera takes way too much pleasure in the bloodshed. But when so much Texas-set entertainment draws on easy stereotypes (TV’s GCB) or familiar genres (the Coen brothers’ True Grit remake), how can you not appreciate this go-for-broke, post–Texas Chainsaw Massacre vision of hell on earth? Steel yourself and give it a chance. You can thank—or curse—me later.

Keep Your Shirt On: Is Matthew getting serious?

How committed is McConaughey to leaving behind the rom-coms that made him a superstar and becoming a dramatic force instead? The encouraging news is that the actor recently finished shooting Mud, the follow-up to Austin-based director Jeff Nichols’s indie hit Take Shelter. Details of the story are scant, but McConaughey plays the title character, an escaped convict living on an island in the Mississippi River who strikes up a friendship with two fourteen-year-old boys. Reese Witherspoon co-stars as Mud’s girlfriend. The film will likely turn up at one of the fall’s prestigious festivals, and—if Nichols’s work with actors like Michael Shannon is any indication—it could be McConaughey’s most ambitious role yet. On the other hand, Mr. Just-Keep-Livin’ doesn’t seem to have entirely abandoned us: next month, McConaughey is also set to appear, shirtless and oiled-up, in Steven Soderbergh’s comedy Magic Mike playing the owner of a salon for male strippers (played by the likes of Channing Tatum and Alex Pettyfer). Old habits die hard.