"Bug" warns us that, just because you're paranoid and delusional, doesn't mean there aren't aphids in your bloodstream.

It's a testament to this intentionally off-kilter drama -- directed by William Friedkin from Tracy Letts's stage play of the same name -- that we actually consider this notion with some degree of seriousness. That's because Ashley Judd and Michael Shannon (who reprises his stage persona) never allow us to categorize the main characters as one-dimensional nut jobs but two emotionally fractured souls who retreat into paranoid delusion. The difference is important because it makes us follow them through some bizarre and increasingly gruesome developments. (Yep, it's a Lionsgate movie.)

At first, we seem bound for an offbeat story with a sweet conclusion as waitress Agnes (Judd) finds herself drawn to the sweet-natured Peter (Shannon), who seems like great long-term relationship material. He's confident and sensitive but also strong enough to protect her from her abusive ex-husband, Jerry (a buff, marvelously menacing Harry Connick Jr.).

As soon as Peter discovers a tiny bug in their bed, however, the reality and good-hearted texture we took for granted become obsolete. And as helicopters hover outside Agnes's motel room, someone rips out their teeth with pliers and two desperate characters pull each other into a downward spiral, we find ourselves in the fascinating no man's land between horror and comedy -- right where this movie wants us to be.

-- Desson Thomson

Contains disturbing violence, sexual scenes, nudity, profanity and drug use.