Conventional (easy, boring) wisdom pegs William Friedkin as the most inexplicable case of a '70s director flaming out early and hard. No simple cause can be found; no evidence of the hubris that led Coppola to build an unsustainable studio, Cimino to destroy United Artists with a single film or Bogdanovich to a series of unfortunate events. Friedkin kept working steadily after the back-to-back success of The French Connection and The Exorcist, but the mainstream critical acclaim never returned.

Ignore the mainstream and delve into the world of revisionist criticism, where anything can be a masterpiece. Consider: In 1980, Friedkin's Cruising was vilified as homophobic by gay rights groups and reviled by critics on general aesthetic principles; this year, a restored print just screened at Cannes. Nor has Friedkin's post-hype career lacked defenders at nearly every stage: certain crazed auteurists will make a serious case for 2000's largely ignored Rules of Engagement, and I'll back them up on 2003's The Hunted, a fundamentally ridiculous chase movie redeemed by Friedkin's decision to completely ignore character and concentrate solely on terse, brutal violence.

This latest release, Bug, illustrates that if nothing else, in many ways Friedkin is the same director he was at the height of his fame. Nervous fractional zooms that seemingly expired 30 years ago and quick but brutal violence prove surprisingly apt in generating tension for another fundamentally ridiculous film redeemed by similarly excellent execution. This time, however, Friedkin has brought the cast along and allowed them to do more than run and grunt. He had to: Bug is an adaptation of Tracy Letts' off-Broadway play, a pared-down five-actor exercise.

In a shady motel room, Agnes (Ashley Judd) chain-smokes, does lines, and answers phone calls with no one on the other end. Her friend R.C. (Lynn Collins) joins the substance abuse orgy after a bar shift and brings along Peter Evans (Michael Shannon), whom she has just met. The seemingly homeless, possibly psychotic -- but polite! -- Peter is a nearly even match for the dead-end Agnes, still tensely awaiting the unwelcome return of her recently paroled, abusive (and presumably crank-calling) ex, Jerry (Harry Connick Jr.). The problem with Peter isn't that he's patently crazy, it's that Agnes is so lonely she's close enough to crazy herself before he sucks her in. One moment Peter's feeling invisible aphids bite him in the night, the next the hotel room's been locked down as a tin-foil-wrapped bunker (to scramble radio waves controlling an army of bugs engineered to spy on people).

Any play called Bug is guaranteed to have a metaphor at work behind the title, though it’s hard to tell exactly which metaphor is at work here. Peter is an ex-soldier, or so he claims, and the increasingly elaborate theories he peddles hint at some kind of generic critique of American violence at home and abroad. Bug eventually gets around to invoking Timothy McVeigh, and seems to be angling for the alternate title Another History Of Violence. Still, whatever point Bug is trying to make gets lost between an increasingly violent tide of blackly comic insanity impossible to take at face value. The film starts as seemingly another entry in a long canon of films glamorizing the American loser -- a world in which seedy motel rooms and depressing honky-tonks take on positively mythic resonance -- and gets more and more deranged, to mostly rewarding effect. And I mean "insanity" literally; anyone squeamish should head for the door by the time Shannon decides to perform some dental work on himself.

Friedkin takes the artificiality of the situation (it's a one-set play) and runs with the claustrophobia, alternating between actor-challenging master shots and nervously shifting angles as necessary. It's as impressive an example as any of filming a play without foolishly trying to artificially "open it up" -- there's no cutting in mid-speech to a different location just for a change of scenery, for example. Friedkin is aided by a superb cast -- Judd regains some street cred, and Michael Shannon demonstrates (as he did in my personal recent Tribeca favorite Shotgun Stories) that he deserves stardom, like, now. Together, director and cast overcome any possible questions about the premise or if anyone's really thought about what's happening here – compared to the conclusion here, which would be unfair to spoil, making crazy Vietnam vets cinematic scapegoats for the last 30 years pales in comparison. Bug may be stupid at heart, but in its own unthinking way, it's way more nerve-wracking than The Exorcist.