I think it'd be tough to argue Clybourne Park isn't one of the best-written scripts we've seen in years. It won the Pulitzer, the Tony, and the Society of London Theatre's Olivier Award. Playwright Bruce Norris does an exceptional job of allowing characters to talk themselves into conflicts far deeper and more personal than they expected. It uses one address, 406 Clybourne Street, Chicago, the same house under contention in Lorraine Hansberry's landmark A Raisin in the Sun, as the battleground for a nation's ethnic tensions. We first arrive in 1959, as Karl Lindner, a minor character in Raisin, reports on his fraught meeting with the black couple who are buying the house. We learn why the current owners are selling, and we cringe as Lindner vents the racist objections of his all-white neighborhood.  Present-day audiences boo Lindner inwardly and congratulate themselves on how far they've come. Except then, in Act II, we're whisked to 2009, when we see how far we haven't.

In the intervening years, Clybourne Park has morphed into an all-black neighborhood. Affluent whites are now interested in the area, which is close to the downtown hub, relatively inexpensive, and ripe for the flipping. When an Anglo couple attempts to buy and replace 406, their efforts are stymied by a homeowner's organization resentful of gentrification. Black neighbors remember the atmosphere of 1959 all too well, and the prospective buyers' ill-advised attempts at humor blow up in their faces. Once again, Norris's characters are all too skilled at digging their own verbal graves. The resulting dialogue is, shall we say, not for the squeamish.

So that's the script, which I highly recommend. But what of Harlequin's production, directed by Scot Whitney? It works, all in all, and benefits from yeoman's work from actor Jason Haws. He plays both the overtly racist Lindner and a passive-aggressive buyer in 2009. Robert Humes is another standout, and Phillip Keiman is effective in two roles despite what he describes as "a weird sort of an American accent." (Keiman emigrated from England two years ago. His "Americans" are flavored with dashes of brogue.) I was, however, troubled by an Act II stage that was scrawled with graffiti. The script specifies an "overall shabbiness," yes, but Harlequin's setting exacerbates a worry of British playwright Kwame Kwei-Armah. He felt the play connotes the idea "that whites build and blacks destroy." (Kwei-Armah wrote his own show, Beneatha's Place, in response to Clybourne Park.)

Lindner, by way of defending himself against charges of unkindness, wails, "Do the boundaries of a neighborhood extend indefinitely?" That is, if I'm obliged to love my neighbor, exactly how wide must my radius of neighborhood be? Surely by "neighbor" we don't mean people who fail to remind me of myself? That's an interesting question, don't you think? Seems ethically relevant somehow.

CLYBOURNE PARK, 8 p.m. Thursday through Saturday, 2 p.m. Sunday, through Oct. 25, Harlequin Productions, 202 Fourth Ave. E., Olympia, $20-$31, 360.786.0151