Bobby (Sean Penn) is a young drifter driving cross-country in a Ford convertable. He has his left hand bandaged and he is transporting a gym bag full of cash to Los Angeles which he owes. After the opening credits, his car breaks down when the radiator hose bursts. He drives to the outskirts of the nearist town which is Superior, Arizona. He leaves his car with the local simpleton and grease monkey mechanic Darrell (Billy Bob Thornton). Darrell tells Bobby about the broken radiator line and tells him that it will take about three or four hours to fix. Bobby takes the gym bag with the money in it, but leaves a pistol in the car trunk.While wandering around the small town, Bobby meets Grace (Jennifer Lopez) a young, attractive Latina woman coming out of a local hardware store after purchasing drapes. Bobby immediately hits on her and offers to help her carry her drapes to her parked car. They introduce themselves to each other and he tells her about waiting for his car to be fixed. When Grace asks about his bandaged hand, he tells her that he recently had an accident. She offers to take him back to her house where he can have a shower to clean up.While in the shower, it is revealed that the "accident" that happened to his hand was in fact a punishment for the overdue debt - two of his fingers were cut off. After his shower he attempts to seduce Grace, who is cold to his advances. He goes to leave, saying he isn't interested in playing games. The two then kiss, where they are caught by Grace's older husband Jake McKenna (Nick Nolte). Bobby, saying he didn't know she was married, tries to leave but Jake punches him in the face.As Bobby is walking back to town, Jake pulls up beside him and offers him a lift. After a casual conversation about Grace, Jake asks Bobby if he would kill her for a price claiming that he is sick of her games. Bobby laughs this off and asks Jake if he's just trying to "rattle" him.A little later, while Bobby is in a convenience store, the store is held up by two teenage thugs. The robbers take his bag with all his money in it but the shop owner takes out a shotgun and kills them both, unfortunately destroying most of the money in the process which takes a blast from the shotgun. Broke and without the means to even leave the town as he cannot pay the mechanic, Bobby frantically calls nearly everyone he knows trying to get money to fix his car. He even calls the gangster he owes money to asking him for money but the gangster angrily refuses. The gangster now knows where Bobby is and sends someone after him.When Bobby is sitting in a bar drinking a beer, he is approached by Jenny (Claire Danes) a troubled and abused teenage girl who flirts with him. Just then, Toby N. Tucker (Joaquin Phoenix) enters. He is Jenny's aggressive and very possessive boyfriend and a local hoodlum who has nicknamed himself T.N.T. who attempts to provoke a fight with Bobby over Jenny's affections. The fight is stopped in time by the town sheriff Virgil Potter (Powers Boothe). Sheriff Potter is stern to T.N.T. who tells him to stay out of trouble, but he is very unfriendly towards Bobby whom he sees as a stranger in town and the sheriff does not like outsiders. After Bobby truthfully explains about why he is in town, Sheriff Potter orders him to be gone as soon as his car is fixed.Bobby goes back to the mechanic, where he finds that Darrell has done additional work and is asking a higher price. He also busted open the trunk of the car and has taken Bobby's gun. A confrontation breaks out which results in Darrell scratching up the hood of Bobby's car. Darrell says that he will continue working on the car and charging more and more for the work until Bobby has the means to pay him. Darrell refuses to take any payment other then cash.Wondering what to do for money, Bobby remembers the offer Jake made to him earlier in the car. He approaches Jake about the deal, who initially passes the comment off as a joke. Bobby says that he could tell Jake was serious about the offer and that he is serious about taking him up on it. Jake tells him that he would need to take Grace out of town and push her off a cliff in order to make the murder look like a suicide.A dream sequence shows that Bobby couldn't go through with it and ends up having sex with her instead as it cuts back into the real world. Grace cuts the sex short however just before he comes, leading Bobby to call her the "Queen of hot-and-cold". Grace reveals that she is not just Jake's wife; she is also his illegitimate child. Jake sexually abused her from a young age and then married her after her mother died. Her mother was found dead at the bottom of a cliff but her death was ruled a suicide. Grace doesn't believe she killed herself. Her death is eerily similar to how Jake told Bobby to kill Grace. Grace then asks Bobby if he would kill Jake, meaning the two of them could steal his money which Grace would not have access to otherwise. Bobby initially refuses, clearly not trusting Grace.Still broke and aware that the gangsters will send someone to find him, Bobby attempts to buy a ticket out of town in order to escape. Although he doesn't have enough money, the clerk gives him the ticket anyway after he becomes aggressive and hostile. After buying the ticket he sees one of the gangsters driving towards him. However, the Sheriff stops the gangster and arrests him for speeding. Thinking he is safe, Bobby is then attacked by T.N.T. who has been attempting to fight him for most of the film. TNT takes Bobby's ticket, rips it up and eats it, causing Bobby to lose his temper and badly beats him up. Just then, Jenny appears and yells at Bobby to stop beating up her boyfriend (!) Bobby reacts with disbelief as Jenny (having just been beaten and punched in the face by T.N.T. minutes earlier), is now comforting him. Bobby angrily storms out of the bus station, seeing how crazy not only Jenny is, but the entire town is.Knowing he is out of options, Bobby phones Grace and agrees with her plan to kill Jake for his money. She instructs him to come on over to the house after dark for the deed to be done. That evening after the sun sets, Bobby breaks into Jake's house while Jake is having sex with Grace, but Bobby accidentally makes a noise. Jake goes downstairs to investigate and finds Bobby, who then tells Jake that killing him was Grace's idea and that he'll kill Grace for just enough money to pay for a car. Grace overhears this and attacks Bobby when he walks into the room. However, she is really waiting for Jake to return so that she can kill him. After killing Jake, Bobby and Grace unlock his safe to find $200,000 in cash. They then have sex in front of his dead body.The next morning, Bobby goes to Darrell to pay him and finally gets his car back. When Bobby returns to the house, Grace's car is gone. Bobby thinks she has run off with the all the money but she shows up at the front door. As they drive off and out of town in Bobby's car, however, they are pulled over by Sheriff Potter. Here we find out that Grace has also been sleeping with him. Grace appears to turn on Bobby, blaming him for Jake's death and telling the sheriff that Bobby just killed her husband. However, just as Sheriff Potter places Bobby under arrest, she pulls out her gun and shoots the sheriff dead. Bobby helps Grace put the sheriff in the car trunk with Jake.As Bobby and Grace are dumping the two bodies off a cliff, Bobby elbows Grace in the nose and takes her gun, telling her that he does not trust her and that when they reach California they will split the money and go their separate ways. Grace says that when she blamed Jake's death on Bobby, she was merely baiting the Sheriff so she could kill him, much like Bobby baited Jake when he said he would kill Grace. The implication seems to be that Bobby would have killed Grace rather than Jake if he'd had to. As they are talking, Grace suddenly pushes Bobby over the cliff, not killing him but severely injuring him. Grace smirks and tells Bobby laying at the bottom of the 60-foot cliff that his suspicions about her were correct; she really is too greedy to split the money in any way, and she used him so she could steal all of Jake's money for herself. She also tells Bobby that SHE was the one who killed her mother by pushing her off the very same cliff, for reasons not made clear.As Grace gets back in the car to drive off, she realizes that Bobby has taken the keys. Bobby pleads with her to come down and help him. She does so, knowing she needs the keys. When she gets close enough however, he strangles her to death with his bare hands. Grace manages to shoot Bobby with her gun before she expires, but it is a non-fatal wound to his right hip. Bobby then makes the grueling journey back up the cliff with a broken leg, a broken arm, his gunshot wound and several other serious and superficial injuries. Relieved that he is finally back in his car (and with all the money), he starts the car to drive off, only for the radiator hose to burst again like it did in the opening scene. Bobby sits back and laughs insanely of his continuing bad luck as he looks up at the bright blue sky... aware that he will now die in the desert heat without anyone to help him now.