Mickey (Edward Burns) & Francis Fitzpatrick (Mike Mc Glone), each in his own fashion, have tried to live by their father's rule: " You've got to do what makes you happy first." Mickey thinks he's happy being a cab driver & living the life of a carefree bachelor -- that is, until he meets Hope (Maxine Bahns), a beautiful, free-spirited graduate student on her way to Paris. Francis thinks he's happy making a killing on Wall Street & being married to his vivacious college sweetheart (Jennifer Aniston) -- that is, until he takes up with Heather (Cameron Diaz), a stunning blonde from Mickey's past. When the two brothers' romantic problems converge in ways neither of them could have imagined, the old sibling rivalry turns into a battle royal.