I'm not sure what I anticipated before watching Bug, but the film completely surprised me. Perhaps since I was at Fantastic Fest, I expected a traditional horror film, with giant disgusting insects flying around and getting squished in a gross way. Bug is not exactly a horror film -- or if it is, it's in the same tradition as Hard Candy. It's a suspenseful movie, but not a gore or grossout fest.

Bug is adapted by Tracy Letts from his stage play -- only five characters have speaking roles, and most of the action revolves around the two leads. Agnes (Ashley Judd) is one step away from being a stereotype of trashiness: living in a crummy hotel room in Oklahoma, working in a honky-tonk with her friend RC (Lynn Collins), and trying to avoid her ex-con ex. One night, RC brings Peter (Michael Shannon) to visit Agnes, and the two connect instantly as friends, even after Agnes's scumbucket ex Jerry (Harry Connick Jr.) turns up. And then Peter notices the bugs in Agnes's bedroom ... blood-sucking aphids.

Normally when someone describes a movie with the phrase "And then ... the bugs," you know what's going to happen. You're going to see some slimy insects and hear that skittering-fluttering noise that scary bugs have made in every horror movie since the 1950s. However, Bug takes an entirely different approach, one that's much more suspenseful and bizarre.

Director William Friedkin knows how to keep us on edge, as he did in The French Connection and The Exorcist. He succeeds again with Bug, even with a small cast in a film that spends most of its time in a single location. The movie does become a little stagy near the end: the climactic scene doesn't work as well on film as it might have in a live theater performance. The audience laughed in the wrong places, and Agnes's big moment of revelation sounded like it belonged on the front of a geek's t-shirt. Fortunately, this doesn't harm the overall effect of the movie too much.

The acting in Bug is incredible, especially Michael Shannon as the magnetic stranger Peter. Shannon gives one of the strongest and most believable performances I have seen all year. I didn't even recognize Ashley Judd as the woman who takes him in. And Harry Connick Jr., I recognized only by his accent (you just can't take the New Orleans out entirely). The dialogue is realistic and rarely hits a wrong note, at least not until the aforementioned climax.

Bug could be set in nearly any era -- we see no computers, and no trendy clothes or furniture. Agnes's hotel room includes a rotary dial phone and a timelessly tacky decor. Her coffeepot is a percolator, and she often wears a plain old-fashioned white slip. Even her name sounds like it's out of the Fifties. The only clues that this is contemporary are references to RC's home life -- she's a lesbian whose partner is trying to gain custody of her child. The old-fashioned touches make the transformation of the hotel room (and the characters in it) in the film's final sequences seem even more striking.

Bug blends paranoia, trust and love into a riveting story, driven by intense characters. You won't be creeped out by insects afterwards, although you might think twice about whom you let sleep on your couch.