A regular old Texan guy named Llewellyn Moss heads out hunting one day and finds the remains of a botched drug deal out in the middle of the desert.
Uh, that's not going to taste good in the stew.
He hunts around some dead bodies and finally finds a briefcase filled with two million dollars. Nice. All he has to do is take the money home and everything will be fine, right? There's no way this could possibly go wrong.
When he heads back out into the desert to bring water to one of the half-dead drug dealers, he gets chased and shot by some men in a truck. As if being chased by drug dealers weren't bad enough, a psychopathic killer named Anton Chigurh decides that, gosh, he'd really like to have the two million that Llewellyn has stolen for himself. Chigurh uses a transponder to track down the briefcase and eventually gets into a street shootout with Llewellyn. Luckily (for now), Moss makes it into Mexico and recovers in a hospital while Chigurh robs a pharmacy to give himself some DIY surgery for his wounds.
While all of this is happening, a meditative old sheriff named Ed Tom Bell tries to track down Llewellyn to protect him from all the bad guys. American drug runners hire a private mercenary named Carson Wells to track down and kill Anton Chigurh, and the whole situation quickly goes belly up. Chigurh murders Wells in his hotel room and tells Llewellyn Moss he'll kill his wife if he (Moss) doesn't bring him the money immediately.
Moss decides to make a break for it and to put his wife on a plane out of the country, but some Mexican cartel dudes catch up with him before he can meet her. They kill him and Sheriff Ed Tom Bell arrives just as the cartel guys get away. Ed Tom retires from the police force because he no longer feels he can keep up with the badness of the world. Anton Chigurh hunts down Llewellyn Moss's wife and kills her because he wants to follow through on his threat to Llewellyn.
(Like a Lannister, a Chigurh always pays his debts.)
To round everything off, Sheriff Ed Tom ends the movie by talking about a dream he had about his father riding into a dark desert.
Hopeful? Despairing? We'll take one of each, please.