It stars Matthew McConaughey as a Dallas detective who has a sideline going in which he acts as a hit man. At the start of the film, he's brought in by a family of rednecks (Thomas Hayden Church, Gina Gershon, Emile Hirsch and Juno Temple) to kill Church's ex-wife.
The rest of the film follows those involved, and what happens after the hit has been accepted by McConaughey
It's a good film. Creepy as heck, but good. My grumbles with the film focus on the fact that Juno Temple really doesn't look 12 (which isn't surprising given what she's asked to do in the film -you wouldn't ask an actual 12 year old to do those things) and the fact that it treats the Texas working class as if they're bed hopping morons.
The fact they're idiots helps the story move along, but part of me was all "Oh come on really?" This ties in some to the age of Temple's character I think. I wonder if the writers found it hard to believe that an ignorant 16 year old redneck could get to 16 without sex, and so made her 12 to make it more believable.
If you can set those grumbles aside, you'll like the film.