Burn After Reading is driven by coincidences, but never feels contrived. The Coen Brothers are among the few filmmakers who could draw up characters so singular in their purposes to make the bad decision after bad decision required to move the story along so effortlessly that it's almost glib.
The plot, such as it is, might almost be called "screwball noir." The characters bounce around, entangling themselves in sex and crime. Two gym workers, Linda Litzke (Frances McDormand) and Chad Feldheimer (Brad Pitt), stumble upon a computer disc containing the memoirs of a disgruntled ex-CIA agent, Osborne Cox (John Malkovich,) who has been fired for his alcoholism. His wife Katie (Tilda Swinton), in preparation for divorce, has also put his financial records on the disc. Linda and Chad contact Osborne and suggest a reward for returning the files, which he interprets as a blackmail attempt. Meanwhile, Harry Pfarrer (George Clooney), a US Treasury agent who is sleeping with his own wife, Osborne's wife, and various women he solicits online--including Linda--gets wrapped up in the reward/blackmail scheme, and on, on, on, on...
In other words, it's one of those movies where everyone's connected, although not everyone gets to meet. We miss out on the perpetually perky Linda pestering Osborne face-to-face, or the happy-go-lucky Chad colliding the frigid Katie. The movie's two biggest stars, Clooney and Pitt, meet for only a moment, although it's long enough to provide the movie's biggest shock, and--depending on your disposition--biggest laugh.
The various motivations are work are preposterous, but endearing. Linda is convinced she needs the money to pay for some cosmetic surgeries ("My job involves interfacing with the public," she tells an unsympathetic health insurance agent) while Chad is so naive he's "really fucking surprised!" that Osborne scoffs at the mention of a reward.
If the Burn After Reading has a flaw, something that makes it merely "another very good Coen Bros flick" instead of "another Coen Bros classic," it's that the characters are wildly entertaining but not always relatable. The Coens pile on so many quirks that it's surprising this problem doesn't drag their films down more often. Only The Hudsucker Proxy, which had characters so affected they just seemed insincere, was derailed by this.
The biggest offender is Katie Cox. Where Linda and Osborne's singular characteristics compelling, Katie just seems one-note. Swinton's performance is fine, but when her only characterization is being an "unrelenting bitch", she turns out to be a drag. It's never explained why she's so sour or, more important, why anyone puts up with her. Maybe she and Osborne shared their misanthropy before he hit his slump, but the chatty, clueless Pfarrer? Her icy demeanor does lead to a great gag when we see her at work. Needless to say, she doesn't make the greatest pediatrician.
More often, however, the actors sketching out oddball, but well-defined, performances which give nice little opportunities for character study. Take how McDormand and Malkovich deal with frustrating phone conversation. Linda gets into a (literally) one-sided argument with an automated phone service that keeps asking her to enunciate. "A-gent. A-GENT!" she hollers, and you get the impression she's the kind who will keep complaining aloud once she hangs up, even if no one's around to listen. Osborne takes the more direct approach, responding to a bank teller's simple request for an account number by screaming "unfortunately I don't sit around all day trying to memorize the fucking numbers! Moron! " Both of them would act the same in person, but it's more telling that they keep up their respective forms of aggressiveness even when they're alone in a room shouting into a phone.
The last scene (some spoilers in this paragraph!) shows how the films' insubstantial ature works for and against the film. In the second and final scene in the office of a CIA Superior (J.K. Simmons in a hysterical bit role), two agents go over the events of the film, unable to make much sense of it, and actually glad that a few people got killed, simply because it gets them out of their hair. (Why they don't seem to think they'll be bothered again once relatives and friends ask where these missing characters went is another question.) Their callousness and cluelessness garner big laughs, sure, but it undermines some of the warmth and depth the characters built up, despite the stylish plot. They even agree to pay for Linda's surgeries just to put the case behind them, but it's played for an off-the-cuff laugh, and brings no on-screen satisfaction for Linda.
Then again, the movie wouldn't work so well if it was played excessively straight. Burn After Reading doesn't aspire to break much ground, but it's amazing well-crafted. And, hey, even "just" another very good Coen Bros. movie is still something to celebrate.