"Burn After Reading" is a lark, but it's an entertaining lark. True to form, filmmakers Joel and Ethan Coen have followed up 2007's Oscar-winning "No Country for Old Men" with a picture very different in tone and setting. In place of internal rumination and serious storytelling, this time they have gone lighter and goofier—if hardly less violent. And, in place of the Southwest, they narrow in on the U.S. capital. The Coens know they don't have any really big and meaningful ideas behind their madness, so they opt to let their first-rate cast loose and have some fun.

For a movie that doesn't add up to much—that in itself is part of the joke—the plot is complicated and labyrinthine. It isn't difficult to follow, but it would take the full length of a regular-sized review to even begin sorting everything out. Cutting the premise down to its essentials, romantically-challenged Linda Litzke (Frances McDormand) and flamboyant go-getter Chad Feldheimer (Brad Pitt) are Hardbodies Fitness Center employees who find a disc of seemingly important codes and files left in the locker room. Thinking that they could earn some money in return if they hold it for ransom—this sounds awfully tempting to Linda, since she needs funds for several cosmetic surgeries—they locate the owner, former CIA agent Osborne Cox (John Malkovich), and start playing mind games with him. As the stakes are raised and further people interweave through the story—among them, Osborne's chilly pediatric wife, Katie (Tilda Swinton); virtuous Hardbodies manager Ted Treffon (Richard Jenkins); and suave, sneaky Treasury Department marshall Harry Pfarrer (George Clooney), whose marriage to children's author Sandy (Elizabeth Marvel) doesn't stop him from secretly dating Katie and Linda simultaneously—Chad and Linda are left helpless to stop the out-of-control fiasco they've created.

"Burn After Reading" is a genre-hopper inspired by everything from screwball comedy to lurid crime thriller. Unless a really assured presence is at the directorial helm, films that alternate in this way usually come up short. That is not the case here, and the Coens earn bitterly funny laughs right next to rising suspense and bleak spurts of violence. There is a sadness in Osborne Cox when he is first introduced—he is accused of a drinking problem and quits his job with the CIA over it, then is smothered by an unloving wife—but that disquieting sense of a man desperate and lost in life is given over to laughs when he announces out of the blue his plans to write a memoir. The highfalutin way that John Malkovich (2007's "Beowulf") continually pronounces "memoir" gets more amusing each time he says it.

Also of humorous note is Linda's meeting with a cosmetic surgeon who prepares to change her whole body, as well as her pathetic date that doesn't stop her from hopping in the sack with him. Little details, like Harry's need to exercise, Chad's addiction to his iPod, and Ted's surprising revelation that he was once a Greek-Orthodox priest, do not necessarily contribute to the story, but are specifically the kinds of rich character details that Joel and Ethan Coen always make sure to include in their screenplays. They add up nicely and aren't superfluous add-ons to the running time.

The viewer remains enthralled with the picture because of the purveying mystery of how everything is going to turn out. To be sure, this is not one of those movies you walk into and correctly guess the ending before the opening five minutes. Without dwelling upon them, the jolts of brutal violence that the Coens mastermind—at least two lead characters end up dead, and far from the two you'd expect—also pack a punch. If the characters grow enough to live and breathe, flaws and all, beyond the script's pages, the previously referenced conclusion cooked up is a disappointment. As the punchline to a joke, it would be ingenious. As the proper ending to a movie, it is anticlimactic. It is almost as if the Coens ran out of steam, backed themselves into a corner, and just decided to throw up the end credits.

Frances McDormand (2008's "Miss Petigrew Lives for a Day") is terrific as Linda Litzke, the arguable heart of the film. A sad sack who looks for love in all the wrong places and is never pleased with her body, McDormand plays Linda with warmth and good humor, a woman whose crafty street-smarts are offset by a daftness she has no knowledge of. As partner and coworker Chad, Brad Pitt (2007's "The Assassination of Jesse James by the Coward Robert Ford") is free and exuberant—not exactly words to describe Pitt's typical roles. He's a joy to watch as he chews up the scenery in the best way. George Clooney (2008's "Leatherheads") is having a blast as Harry, a man who doesn't understand the meaning of monogamy and doesn't care to learn it. Though deceiving of others, when things don't go his way the viewer almost feels sorry for him. Clooney is too likable to despise. And in a typecast part that she nonetheless makes memorable, Tilda Swinton (2007's "Michael Clayton") is slyly acerbic as Katie, an ice princess who has no idea how emotionally cold she is to people.

If "Burn After Reading" has any purpose outside of entertainment, it is the snarky (but not invalid) comment made about the self-absorption inherent in all of us. Certainly, the ensemble of part-zany, part-tragic figures would all live happily ever after if they considered the world around them and weren't so involved in their own problems, or (as the case may be) lack thereof. Slickly shot on location in Washington, D.C., and making great use of the district's landmarks, cinematography by the wonderfully resourceful Emmanuel Lubezki (2006's "Children of Men") is ace. The jittery anxiousness he helps to build in a scene set in a closet also stands out aesthetically. It is a shame that the slight but undeniably inventive "Burn After Reading" isn't all that it could have been—the wrap-up really does leave something to be desired, even as it resounds loud and clear—but a minor work on the Coen brothers' résumé is still better than, or as good as, most other filmmakers' best.