David Auburn's Proof is a first-rate, multiple award-winning drama. Crisply written with lived-in, matter-of-fact dialogue, constructed so perfectly it unfolds like layers of wrapping paper coming away from a gift you never knew you wanted, Proof is an irresistible mystery-drama about a family of mathematicians grappling with death, mental illness and a hidden notebook containing a history-shaking mathematical proof. The play has only one major flaw: it is too irresistible, and is now in serious danger of being overperformed. It's the Fantasticks of nonmusicals. In the North Bay, where it has been staged three times in the last three years (four if you count Mendocino), it is scheduled for a run in Napa this summer and just opened in a four-weekend run at the Pegasus Theater Company in Monte Rio.

Confidently directed by Jacqueline Wells, this is a Proof with the wisdom to let its characters sit and talk to one another without leaping up and running about the stage every other line. (Why do so many directors allow their actors to do that?) In this Proof, the focus is firmly on the emotional connections between the characters. As Robert, the brilliant mathematician whose grasp of reality has been slipping for years, Peter Cooper captures the frailty of the once-great man while maintaining a powerful sense of wounded self-respect.

Rachel Hempy, as his youngest daughter, the would-be mathematician Catherine, is less layered and complex than the character is often portrayed, choosing instead to play her as younger, lighter and less emotionally wise. She seems, after years of being forced into caring for her mentally ill father at the expense of her own life, somewhat emotionally arrested. It's a strong choice and an effective one, allowing her to play her passive-aggressive flirtation with visiting math geek Hal (a superb Donovan Dutro, easily the best Hal I've seen so far) with a extra dash of giddy girlishness, something that would not have worked with a darker, deeper Catherine.

Conversely, as Claire, Catherine's sensible, less-creative sister, Maria M. Giordano brings more complexity to the role than usual, making her Claire a person who may have distanced herself from her less stable family, but who--for all her organization and detail-control--is clearly cut from the same cloth.

Working on a wonderfully expressionistic set by David R. Wright (a Chicago back porch painted entirely--walls, floors and deck--in autumn leaves and mathematical equations), the well-matched cast misses the mark here and there, throwing away some important lines in an apparent effort to avoid melodrama. But in the end, they create a memorable Proof that emphasizes the wounded hearts beating away beneath all those beautifully brilliant minds.

Proof runs Thursday-Sunday through May 12. Thursday-Saturday at 8pm; Sunday at 2pm. Pegasus Theater, 20347 Hwy. 116, Monte Rio. $12-$15. 707.522.9043.

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