Donovan Donaly (Geoffrey Rush), a soap opera producer, comes home to find his wife, Bonnie (Stacey Travis), having an affair with a pool cleaner named Ollie (Jack Kyle). He brandishes a gun to shoot Ollie, but his wife stabs him in the bum with his own pointy Lifetime Achievement Award trophy. Ollie and Bonnie run away while Donovan shoots at them from a balcony, later taking pictures of his wounded behind as proof that his wife attacked him first.
Miles Massey (George Clooney) is the U.S.'s top divorce attorney, creator of the "Massey Pre-Nup", a prenuptial agreement which has never been successfully challenged -- meaning that no party to it can benefit financially in the event of a divorce. He becomes Bonnie's lawyer, assuring her he will win the divorce case and leave Donovan with nothing. During a trial hearing, he confides to his associate Wrigley (Paul Adelstein) that he is in the middle of a mid-life crisis, and is feeling bored with life. He compares himself with Attila the Hun, Ivan the Terrible, and Henry the VIII, all of whom destroyed all their opponents. Miles has done everything, seen everything, bought everything; he is seeking the ultimate challenge.
Meanwhile, Rex Rexroth (Edward Herrmann) is having a sexual role-play session with a blonde temptress in a cheap motel when a private investigator named Gus Petch (Cedric The Entertainer—note the same middle name as above) bursts into the room with a video camera and records everything. He brings the video to Rex's wife, Marylin Rexroth (Catherine Zeta-Jones), who remains very calm and reveals that the video is her ticket to wealth and independence. Rex tries to talk to Marylin, but she sends her rottweilers to chase him off their property. Rex seeks counsel from Miles Massey, who assures him that, despite the video, he will win the divorce case. Marylin consults with her girlfriends, wealthy fellow serial divorcées, including Sarah Sorkin (Julia Duffy). She warns Marylin to beware of Miles Massey.
After Marylin and her lawyer, Freddy Bender (Richard Jenkins), fail to agree with Miles, Rex, and Wrigley on a divorce settlement, Miles asks Marylin to dinner where he decides that Marylin is the challenge he's been looking for. He hires Gus Petch to take pictures of her diary. Later, in divorce court, Miles exposes Marylin's calculating life by presenting a witness named The Baron Von Espy (Jonathan Hadary) who testifies that she asked him several years ago to find her a rich husband who could be easily manipulated. Because she winds up with nothing from the divorce, she swears revenge on Miles. She contacts Donovan Donaly, who is now living on the street, to help her. Herb Myerson (Tom Aldredge), Miles's boss, congratulates and praises him lavishly for his fine work.
Soon after, Marylin shows up at Miles's office with her new fiancé, an oil millionaire named Howard D. Doyle (Billy Bob Thornton). She signs the Massey Pre-Nup and invites Miles to their wedding. During the ceremony, Howard rips up the pre-nup and eats it in a flamboyant demonstration of his love. But not long after the wedding, Marylin divorces Howard and takes most of his money, making her a very rich woman.
Months pass. Marylin bumps into Miles at a convention of divorce attorneys in Las Vegas. They discover that they both are lonely people despite their wealth; she reveals that her best friend Sarah Sorkin has died from an aggravated ulcer. Miles is besotted with Marylin and marries her on the spur of the moment. Happy and content in their new marriage, they need no pre-nup. Miles has become a changed man and decides to abandon divorce suits in favor of pro-bono work in East Los Angeles. However, while celebrating this decision, Miles discovers that Howard D. Doyle is in fact an actor from one of Donaly's soap operas, and not really an oil millionaire. Marylin has no money of her own. Even her friend Sarah Sorkin is still alive. Marylin has thoroughly tricked Miles and now his wealth is exposed to Marilyn's asset stripping.
Miles' boss is most displeased with this turn of events and demands that something be done about it because she has humiliated their law firm. The boss hires an hitman named Wheezy Joe (Irwin Keyes) to kill her, but before the plan is completed, Miles learns that Marylin's ex-husband Rex Rexroth has died of a heart attack, leaving millions to Marylin. Miles now stands to *benefit* from a divorce, so he attempts to stop the assassination, with tragically comic results. At the end, Miles and Marylin meet at a divorce attorney's office to hammer out a deal. Miles is still in love with Marylin and shows his trust in her by retroactively signing a pre-nuptial agreement. Marylin destroys it, and they kiss and reconcile. Marylin tells Miles that she suggested to Donovan Donaly a TV show about divorce à la America's Funniest Videos starring Gus Petch. The show is a success, and everyone lives happily ever after.
(Adapted from Wikipedia)