Made on the cheap for the horror-loving kids at Lionsgate, this freaky-deaky psycho-thriller from New Hollywood survivor William Friedkin is more inventively unsettling than anything the auteur has mustered in the quarter-century since twisting little Linda Blair into a satanic spewer of pea soup and F-bombs. (It's based on Tracy Letts' off-Broadway hit play.) Mostly the movie confines its creepy-crawly head games to one dingy motel room, where an Oklahoma honky-tonk barmaid (Ashley Judd) holes up wi th a wigged-out stranger (Michael Shannon) just back from major combat operations in the Middle East. To varying degrees, these two damaged, desperate souls let their imaginations run wild in tight quarters, leading to full-on madness and an erotic/violent climax right out of Almodóvar's Matador. Flamboyantly absurd, with the self-mutilating vet suffering an itch he can't sufficiently scratch, the film often plays like a satire of the lefty paranoia cinema that was big in Friedkin's Hollywood heyday. And yet its psychological insights into mental illness remain acute and even sensitive. Indeed, as Judd's Agnes undergoes an extreme, insectlike metamorphosis, Bug itself turns from a horror movie into something like a love story.