No Country for Old Men opens with a monologue by Sheriff Ed Tom Bell delivered after the main events of the narrative, in which he speaks about a brutal killer. Every chapter opens with Bell’s monologue and contains recollections and thoughts that pertain to the evil that Bell sees in the changing world. The narrative starts with a focus on Llewellyn Moss, a Vietnam vet, who is hunting in the barren terrain of Southwest Texas. He stumbles across a drug deal gone wrong and makes the fateful decision to take a case of money containing more than $2 million. That evening Moss returns to bring water to the only survivor of the shootout, but the man has been killed, and a pair of drug dealers chase after Moss. Even though he escapes, he knows they will soon identify him through his truck. Moss sends his wife, Carla Jean, to her mother’s house in Odessa and goes on the run.

Meanwhile, an unnamed man has killed a deputy sheriff who arrested him and then a driver in his successful escape. We learn this is hitman Anton Chigurh, a sociopathic killer who wields a bolt weapon and uses coin flips to determine if people will live or die. Chigurh has heard about the shootout and meets up with two men who take him to the scene where he learns what he can. Then he kills the men and heads out to look for Moss. Sheriff Bell attends the scenes of both of Chigurh’s murders and the shootout. Bell knows many of the constituents in his county, and he recognizes Moss’s truck and later learns that Moss and Carla Jean have left town. Bell believes it is part of his job to save them. 

Moss first stops at the city of Del Rio, but he can tell someone has found him, so he heads to the border city of Eagle Pass instead. In his room at the Hotel Eagle, Moss discovers a transponder hidden among the bills in the case of money. He remains in his room where Chigurh, using the transponder’s receiver, tracks him. Moss gets his gun on Chigurh, but instead of killing him, Moss runs. Chigurh shoots at him at the same time a car with several men working for the drug dealers pulls up and starts shooting. Although injured, Moss hides the bag near the border and escapes into Mexico, where he goes to a hospital. When he wakes up, he finds a man named Carson Wells at his bedside. Wells is yet another hitman, but his job is to recover the money and kill Chigurh. Wells has come to the Hotel Eagle to trace Moss’s steps and find the money. He only needed a few hours to find Moss in Mexico. Now he wants to help Moss out of this jam, but Moss refuses his offer.

After the shootout in Eagle Pass, Chigurh leaves town and takes several days to recover from his injury. Once he is back on the road, he hears the transponder’s receiver going off. It draws him back to the Hotel Eagle where he finds it in Moss’s room but no money. Chigurh stakes out the hotel, where Wells also is staying. When Wells returns from Mexico, Chigurh pulls a gun on him, forcing him to Wells’ hotel room, where Chigurh kills him. Meanwhile, after speaking with Carla Jean, Moss has changed his mind and decided to get help from Wells. He calls Wells’ number, but Chigurh answers and tells Moss to bring him the money and he will spare Carla Jean’s life though he will kill Moss. In response, Moss declares that he is coming after Chigurh. Moss retrieves the hidden money and plans to kill Chigurh and then meet Carla Jean in El Paso, where she has gone to wait for Moss. Carla Jean also calls Sheriff Bell, who contacted her earlier, and hints that she will have information if he promises not to hurt Moss. After killing the man who hired Wells, Chigurh starts tracking Carla Jean as well. Meanwhile, on his way to El Paso, Moss picks up a teenage hitchhiker hoping for a new start in California. They stop in a small town where Moss gets them each a motel room. He doesn’t know that a pair of Mexican hitmen and Chigurh, presumably having tapped Carla Jean’s phone, are speeding to his location. The two hitmen arrive first and kill Moss and the hitchhiker but fail to find the money. Sheriff Bell is called to the scene. He identifies Moss’s dead body and then has to break the news to Carla Jean. Later that night, Chigurh finds the case of money, which he returns to an unidentified businessman. 

Carla Jean goes home to Odessa, where Chigurh catches her. She points out that he doesn’t need to kill her because he already has the drug money. Killing her will bring him nothing but Chigurh insists he must follow his code of ethics and can’t break his word to Moss. When Moss refused to bring him the money, he set in motion a course of events that must end with Carla Jean’s death. Telling Carla Jean he has no choice, he shoots her. After leaving her house, Chigurh gets in an accident and stumbles off, injured. Two teenage witnesses steal his gun from his truck. 

Sheriff Bell visits his uncle, Ellis. Bell shares the secret that he deserted his squad during World War II, even though the men were either dead or dying. Bell has felt guilty ever since. The experience even drove him into law enforcement in an effort to make up for his past. Bell is drawn back to the case when the police find the gun that killed Carla Jean, but he learns nothing from the witnesses to help him identify Chigurh. All the evil and death he has recently witnessed get to Bell. He decides to quit his job because he can’t face having to hunt for another man like Chigurh.