Where Bug succeeds, it does so by inducing in you the same kind of on-edge, constant low level of terror Agnes lives with on a daily basis, the kind of ordinary distress with modern living that afflicts way too many people. Agnes drinks too much. She does drugs. She has, at best, one friend to speak of. She is dealing, as the film opens, with ongoing harassment by telephone from her ex-husband, who’s just gotten out of prison. And she’s got other ghosts haunting her, too, we later discover. Ashley Judd (De-Lovely, Twisted) is appropriately worn-out and grungy as Agnes, makes the waitress a fragile, desperate creature at once sympathetic and shockingly weak, and she’s the best reason to check out this flick. (Harry Connick Jr. [My Dog Skip] shows up later as Agnes’s deliciously disgusting ex, and he’s a revelation, too.)

So when I tell you that you’ll be itching all over by the time Bug is finished with you, you have to know that it’s because it gets under your skin not in the way of sadistic slasher films, burning your eyes out of your head with gruesome, violent imagery you’d rather never have seen, but because you will have become convinced -- almost -- that Agnes’s descent into madness is an entirely reasonable reaction to where life has taken her. Even though that sounds crazy, from the perspective you’ll have once you leave the theater and come back to sunshiny reality. There aren’t armies of creepy-crawlies all over the screen here -- the creepy-crawlies get into your mind.

And yet, Bug isn’t entirely as ooky-spooky as it thinks it is -- the more it embraces its ethos of nervous paranoia and conspiracy-spiked secrecy, the less satisfying it becomes, as if putting a concrete name to the madness somehow makes it less mad. See, Agnes takes up with an intriguing drifter, Peter (Michael Shannon [Lucky You, Criminal], who’s long been a reliable second and third banana but demonstrates here he deserves to break out), a shy, gentle man who nevertheless has some strange, violent issues about insects, government plots, and how machines are inherently unworthy of trust. The bugs under his skin, for instance, were put there as part of an experiment conducted on Gulf War I vets... and Agnes is so vulnerable to human attention, to her own need to care for another person, that she quite readily buys into his delusion. If it is delusion.

Director William Friedkin’s (The Hunted, The Exorcist) cinematic spin on Tracey Letts’ stage play, like his lazy attention to the prickly details of the ceiling fan, can’t totally overcome a certain blocked-in feeling -- which isn’t quite the claustrophobia it should be -- and a predictable staccato, stagey rhythm fights with the otherwise jittery atmosphere. But the real dissatisfaction comes, perhaps, out of the inevitability of the narrative itself: As the new friendship Agnes and Peter quickly fall into takes form, and their shared experience leaves them with fewer options for escape, the narrowing of possibilities for them as characters and for the larger story chips away at what had started out as a Philip K. Dick-ian, Williams S. Burroughs-esque nightmare, wild and unrestrained, to frame a nightmare that is rather more prosaic, for all its overt craziness. The itching you’ll be left with will be, partly, one of disappointment.

(Technorati tags: Bug, William Friedkin, Ashley Judd, Harry Connick Jr, paranoia)