In the immortal words of Wayne's World: "You'll laugh, you'll cry, you'll hurl." What you won't do is shrug Killer Joe off as just another movie. Already notorious for having been slapped with an NC-17 rating in the United States, the film is more ferocious than could reasonably be expected from a septuagenarian director (or from anybody short of Sophocles or the Marquis de Sade). But there it stands as a sharply carved career bookend in the life of director William Friedkin, who won an Oscar in 1971 for The French Connection but only truly cemented his legend two years later with the shocks of The Exorcist. That film was about a fractured family unit under assault by demonic forces, and in a way, so is Killer Joe, although its contents are less supernatural than they are Southern Gothic: This time out Friedkin sprays engine grease and sweat in lieu of pea soup.
The everything-but-the-truck-stop-kitchen-sink tone is courtesy of playwright Tracy Letts, who won a Pulitzer Prize in 2008 for his August: Osage County but is hardly a staid and respectable dramatist. His great talent is for cramping volatile characters into confined spaces and letting them claw at each other, as they did in Bug (2005), his previous collaboration with Friedkin. Killer Joe, originally written for the stage in 1993, isn't Letts's most mature work but it has a barbed narrative hook: Up to his beady little eyeballs in debt, Lone Star state wastrel Chris (Emile Hirsch) contrives to have his mother killed for her life-insurance policy. His family members, including no-account pater Ansel (Thomas Haden Church) and his sneering new wife Sharla (Gina Gershon) are down with the plan – until the assassin shows up and it's clear that all parties are in well over their heads.
As the titular Killer Joe, Matthew McConaughey gives the performance of his career. Stealthily elegant in his long coat and gloves and flicking his Zippo with a nimble trigger figure, his Joe Cooper is a predatory interloper who quickly infiltrates his client's clan, surveying their weaknesses at a glance and striking with a spider's poisonous precision. If the character's late-breaking condition that Chris put up his baby-doll little sister as collateral against the as-yet-uncommitted murder is the work of an evil mind, it's also the only gesture of interest anybody shows to Dottie (Juno Temple), who in the best noir tradition is probably smarter than she looks.
The plot of Killer Joe is twistier than an East Texas back road but it's primarily a mood piece. Friedkin and Letts aren't working subtly here – things literally open on a dark and stormy night – but the combination of narrative propulsion and bracingly nasty dialogue ("Are you done fumigating the gates of hell?" asks Ansel after Sharla freshens up) breaks down the viewer's defences. And then, when he has us where he wants us – giggling and nervous – Friedkin the horror-meister returns, staging a couple of sequences so brutally and baroquely over the top that they'll probably be discussed for a long time. Credit goes to the actors (especially Gershon) for giving almost as good as they get in seriously demanding roles, and to Friedkin for having what it takes – guts, chops and a refreshing lack of artistic caution – to bring things thundering home.