In this season of bloated epics and unfunny comedies, there's a wonderful breath of fresh air in the quirky and delicious "Mr. Brooks." With the most unlikely cast in ages, all moving gracefully into middle age, and a script that's tight and fascinating from beginning to end, this is the sleeper we've been waiting for.

"Mr. Brooks" is the story of a serial killer, the so-called 'Thumbprint Killer,' played by Kevin Costner. Mr. Brooks, who is also a wealthy businessman being honored at the beginning of the film as the Man of the Year in Portland - a man who feels himself addicted to killing, attends AA meetings and recites the Serenity Prayer when he feels the urge coming on. But he also has a doppelgänger who rides with him, talks to him, is both his id and his ego, encouraging him but also mindful of the traps to avoid as a killer. It's William Hurt, whom he calls "Marshall," and as the two of them discuss both his compulsions and his methodology; they're the two brightest characters in the film, and to watch these two laid-back actors doing what they do best is a great pleasure.

And then there's Detective Atwood (Demi Moore, in her best performance in years), who's been on the trail of the Thumbprint Killer for a long time but now is also targeted by an escaped convict called the "Hangman Killer" and by her gigolo husband who only wants money as the price of a divorce. And now a guy who photographed Brooks doing a killing wants - what does he want? He wants to join in on the fun and go along for the ride on Brook's next killing. Oh, and one thing more: Brooks's daughter Jane, now unexpectedly home from college, may have inherited his gene for killing.

Think of all the ways this scenario could go wrong. How it could become laughably ludicrous, or just piled up with excess baggage. Instead, what's fascinating about all this is that the writers, Raynold Gideon and director Bruce Evans, keep every ball in the air without even a slipup. And Evans directs the film with a superlative hand; even his placement and lighting of Marshall, in the back seat of Brooks's car, coming out of a kind of blackness to talk to Brooks, works perfectly. Normally I have a problem with Hurt's nasal voice and slow delivery, but here he's much more animated, and his lines are always fascinating to hear. And Kostner uses that laid-back persona of the old athlete who knows how good he is, but still makes us believe that he is, as he says, addicted to killing. "Mr. Brooks" is, so far, the sleeper of the year.