The film begins with Nick visiting Ken Lacey, the sheriff of a nearby county, ostensibly to ask for advice about two pimps who regularly insult and bully him. Lacey mocks and belittles Nick, boasting that if any pimps disrespected him, he would shoot them dead on the spot. Nick briefly and accidentally reveals his actual intellgience, but only Deputy John notices, which Nick does in return. Before Nick returns home, he invites John to dinner where they have a conversation that fades to black when the pleasantries end. Later at midnight Nick goes to see the two pimps, who it is revealed Nick has been taking bribes from. As they berate and mock him as usual, Nick fatally shoots them both, cleverly timing it so riverboat's whistle covers up both gunshots
Sheriff Lacey comes to see Nick, having become concerned that Nick might actually kill the pimps and make Lacey complicit in the crime. Nick reassures Lacey, then deceives him into getting drunk and than staying at the pimps' brothel and boasting to the town that he had 'taken care of' the pimps.
The next day, state congressman Robert Lee Jefferson berates Nick for never making any arrests. Jefferson warns Nick that he will face a strong opponent in the coming election from Sam Gaddis. Nick replies that the people don't really want him to do his job, that they enjoy petty crimes such as gambling, public drunkenness, and prostitution, and that if he started to arrest people for such crimes he would have to arrest the whole town. He agrees that Gaddis is a man of moral character "regardless of those rumors about him playing around with the cows or getting that minister's daughter pregnat and tricking her into an abortion," planting the seed for those rumors and others to spread to spread.
Nick then goes to find Tom Hauck, the husband of Rose Hauck with whom Nick is having an affair. He finds Hauck drinking and fishing at the river and kills him by getting him even more drunk until he falls unconcious, and tipping over the boat so it looks like he just drowned while in a stupor. Nick then tells Rose he has killed her husband; she is overjoyed, and they have passionate sex.
Nick comes up with a way to get rid of Myra, her brother Lennie, and Rose all at once. He manipulates Rose into telling Lennie that she has seen him having sex with Myra. Unbeknownst to Nick, Myra really is sleeping with Lennie, and confronts Rose at her house. Rose shoots both Myra and Lennie dead. He shoots her dead, framing it as Lenny having done so, having gotten one last shot off before he subcome to his wounds. When he breaks the news to the town, he confirms rumors that Lennie had been the "Peeping Tom" mentioned eariler, and then lies saying Rose called him to report Lennie and that he agreed to have him sent to a mental ward for Lennie's own good; the gunfight being Lennie and Myra trying to threaten her or explain themselves, and things getting out of hand. Everyone buys his story, propelling Nick's popularity to new heights because of the tradgey.
State Congressman Robert Lee Jefferson and a few other shreiffs, including John Landsdale, and Texas Rangers confront Shrieff Corey the next day. For a brief moment he thinks he's caught as Jefferson and other grill him about his relationship with the pimps, his wife and "brother-in-laws" murders, and his friendship with Shreiff Lacey. He quickly realizes that Lacey is the one in trouble, however, just as planned between him and Landsdale. He's just being asked to testify as an eye witness against Lacey; it's going to be a open and shut case though given "the evidence" and that one of the pimps was the black sheep of an extremely powerful and wealthy family. When it the room clears out, the conversation gets better for Corey. Indeed, the reason the conversation shifted over to his wife's murder was because Corey's future as a law man is over at the next election: while he will always be popular now given the circumstances, his own brother in law being a deviant and the scandal of the triple homicide is too much. Instead, Robert Lee Jefferson wants him to run for congress next year, instead of him! Some judge died anyway and he's getting his spot; might as well go to a popular Republican who he can trust and can keep the seat safe. Landsdale smiles and tells him he's going to get the state congressional postion and won't be the interium Sheriff's position for long either; he was hoping to cheer Nick up by taking him out for dinner tonight.
The two have a conversation without prying ears confirming what the audience suspects at this point: Landsdale and Corey planned to frame the pimps murder on Lacey from the beginning. He asks Nick if they should arrange for Lacey to 'kill himself' behind bars. Corey tells him no, to let it go to trial because of all the murders and his prediction Lacey will get himself killed when he's convicted, by another inmate, which he will be because of the reasons Jefferson stated eariler, even if there are enough holes that it could be overturned if Lacey had the time to keep pushing. "Well, Sheriff Lacey, put a lot of men behind those bars, and he'll be sharing a bunk bed with some of them. Man like that isn't going to get a warm reception, might in fact expect a very cold one. Colder than it can even get in a Texas night, I tell you what. Now I ain't saying you'd be wrong, wanting to silence him, but I ain't saying you're right either. The Lacey made his bed, now we just have to let him die in it."
