When a group of decadent Hollywood filmmakers invades a sleepy New England town, they immediately set their sights on the stained glass window of the historic firehouse. ``It's the only thing worth anything in this town,'' says local bookstore owner Annie Black (Rebecca Pidgeon). The movie people want to destroy it so they can shoot a love scene through the window.

This brilliantly enjoyable movie is about what happens when truth and purity get in the way of the needs of the rich and famous. Writer-director David Mamet - in perhaps his best film - portrays a world driven by expediency, deceit and base instincts, but where the corrupt and the innocent may be able to get along in the end.

The film races along, throwing out witticisms and clues about the plot as it draws us into the lives of the big-city honchos and locals alike. The setting and cinematography is impeccable, caressing small-town life even as Mamet shows us cracks in the façade. Lively incidental music reminds us not to take it too seriously.

The ensemble cast works together seamlessly. The fictional filmmakers are relentlessly self-involved. It's priceless to see the locals' reactions to their world being turned upside down and how they quickly learn to exploit the situation.

Pidgeon is at her clear-eyed, honest best. William H. Macy is desperately funny as the fictional director Walt Price, a manipulative, charismatic man who switches instantly from charm to abuse to get what he wants.

Alec Baldwin and Sarah Jessica Parker give brilliant send-ups of themselves: Baldwin plays the gracious movie star who can't stay sober or celibate, and Parker is the starlet who drops her clothes in a blink to get what she wants. ``It's a script conference,'' she explains.

Philip Seymour Hoffman portrays screenwriter Joseph Turner White with the earnestness he brought to Boogie Nights as he struggles to maintain the integrity of his creation against a mounting number of obstacles. The screenplay is about purity and second chances, he says, and so is Mamet's film. We're rooting for you, Joe, both in the budding romance with Annie and in making your movie ``The Old Mill'' even though the mill burned down 15 years ago.

Mamet at his best ties up all the loose ends. State and Main does not disappoint, with small references and repeated phrases all coming back full circle. You really want to watch this movie twice in a row to enjoy all the fun.