`A SIMPLE PLAN' BASICALLY WORKS.

Byline: Bob Strauss Daily News Film Critic

``A Simple Plan'' does so much so well that it's a shame it ends up so fundamentally, well, simple.

A beautifully shot, wintry film noir that signals a profoundly mature step in director Sam Raimi's development, the movie digs deep into areas of behavior good people never want to know they possess. ``Simple Plan'' also boasts impressive tonal consistency, a good sense of paranoia, great performances, mesmerizing set pieces and an intelligence rarely found in thrillers today.

The problem is that precious little in this movie comes as a surprise. While lead actors Bill Paxton, Billy Bob Thornton and Bridget Fonda play their small-town Minnesota characters with depth, passion and something like the spontaneity of real people, the outline of their moves is predetermined almost to the point of ritualism. If you've ever seen a movie where a trove of unearned money destroys everyone that touches it, then you know where this unforgiving morality play is headed from the opening credits.

Getting there, however, is all the fun. Based on Scott Smith's novel (he also wrote the screenplay), the film spins a lesson of biblical dimensions out of the classic concept that a little knowledge is a dangerous thing.

Our in-over-his-head smart guy is Paxton's Hank Mitchell, and his grand tragedy lies in his painful discovery of how thorough a jerk he can be. The only college graduate from a family of former farmers, Hank initially sees nothing wrong with his humble accounting job at the local feed store. It's enough to afford him a nice, modest house, which his massively pregnant wife Sarah (Fonda) seems content enough in.

Compared to that of his dim-witted, unemployed older brother Jacob (Thornton), Hank's life is indeed perfect. Every inch the Midwestern geek with his long greasy hair, Coke-bottle glasses and perpetually stubbled cheeks, Jacob has lived in a trashed-out apartment with his mangy dog ever since the family farm got foreclosed on.

When Hank, Jacob and Jacob's only friend, a drunken lout named Lou (Brent Briscoe), find some $4 million in a downed airplane, it's educated, self-controlled Hank who decides to sit on the obviously illicit money until spring, then dig in if nobody claims it.

The subtlest changes come across Hank, though. He's not wrong in thinking he's the most decent, smartest conspirator involved in this increasingly birdbrained and blood-spattered cover-up. But it's amazing how his every strategy reveals an unexamined contempt for everybody he thought he held dear.

Beautifully balancing Hank's descent into his own misanthropy, Jacob's wounded human dignity blossoms under pressure (even as his limited intellect cracks from the same force).

Raimi, a cracked near-genius who usually makes overcaffeinated comic book movies like ``Darkman'' and ``The Evil Dead,'' reveals these layers of humanity at a deliberate but perfectly timed pace. He also knows exactly when to goose the proceedings along with judiciously constructed shock bits; the scene in which Hank insensitively forces Jacob to choose between his only friend and his only brother may be the best stretch of film since Spielberg's Omaha Beach.

All that said, the mechanistic puritanism that drives ``A Simple Plan'' is hard to take. After the recent ``Waking Ned Devine'' made such worthy fun of knee-jerk moralism and ``Very Bad Things'' splattered the whole concept into a million preposterous pieces, you just wish these fascinating individuals could live a nightmare that was worthy of their complexity.

THE FACTS

The film: ``A Simple Plan'' (R; violence, language, substance abuse).

The stars: Bill Paxton, Billy Bob Thornton, Bridget Fonda, Brent Briscoe.

Behind the scenes: Directed by Sam Raimi. Written by Scott B. Smith, based on his novel. Produced by James Jacks and Adam Schroeder. Released by Paramount Pictures.

Running time: Two hours, one minute.

Playing: Beverly Center Cineplex, West Hollywood; Century 14, Century City; Cineplex Broadway Cinemas, Santa Monica.

Our rating: Three stars.