This is why we need Pittsburgh Playwrights Theatre. Sure, it's made a name doing full-bodied versions of August Wilson's plays, and other Pittsburgh playwrights on its roster range from George S. Kaufman to founder and artistic director Mark Clayton Southers. But in "Valu-Mart," it's found a play that has won playwriting awards around the country without, amazingly, ever being produced. Apparently it's too controversial.

So Pittsburgh Playwrights has stepped up with a skillful, engaging production of what turns out to be an audience-friendly play with substance. It's just what a playwright needs to take his work to the next level, even while succeeding at this one.

Granted, the concept of "Pittsburgh playwright" has been stretched, right into West Virginia, but don't we think of that as Pittsburgh's backyard? West Virginia playwright Sean O'Leary has always had a foothold here, partly through his father, Hal, who has acted here many times.

Besides, this is a no-nonsense, Pittsburgh kind of play, a taut tale of five employees in a store something like K-Mart or Walmart who are being held in a locked employee lunchroom while they're taken out one by one to be interrogated and strip-searched in pursuit of a missing key to a jewelry display case.

So "Valu-Mart" sets up as a whodunit. But ultimately it's really a drama of character revealed under pressure, achieving the dimension and interest that make up for its slight didacticism on behalf of prejudice-blind race (or class, or gender, or age) relations.

The six characters are the thing: three men, three women; three mature, three young; three middle class, three not; three white, three black. As is usual in America, the racial divide seems the most important, but as time passes and alliances shift, others come to the fore. Consciousness is raised and new bonds are formed. The true enemy is the divide-and-conquer strategy that governing elites have always practiced. (I suppose they teach them in business school.)

The characters provide the drama -- their conflicting attitudes, shifting alliances and growing insight. They even work toward a kind of tenuous solidarity. And the play's enigmatic ending leaves us with further questions, as any good play should.

As director, Mr. Southers' chief achievements are the casting and the confining feel of the set, in which a small audience sits on three sides of the action, looking down at it, themselves isolated by chest-high walls. It feels like a holding pen, or maybe a jurors box. Laugh with alarm and sympathize with foreboding -- that's how "Valu-Mart" messes with our participatory reactions.

Among the play's virtues are frank street language tinged with poetry. And anyone will savor the framing irony of the disembodied voice's messages of shopping good cheer about "trusted employees" and "what you value about Valu-Mart." Meanwhile, it feels like a faceless corporate state, within which the five hapless employees and even the security guard face real ethical dilemmas. And have I mentioned how funny it is, rich with the laughter of recognition?

But it's obvious the play should be tauter, some 90 minutes of continuous playing time without intermission. Instead, tension leaks away, and energy is wasted building it back up in Act 2. The early part of Act 2 seems repetitive, even though the whole play, intermission included, now runs just over two hours. The other shortfall is that not all the characters are equally rich. The older woman in particular is less specific, her dilemma less felt.

But in general these are juicy roles, realized with impressive, up-close realism. The flashiest and most impressive acting is by Gregory Parker as Khalid, the young hothead who is actually very shrewd. He's a perfect foil to the guru figure, his former English teacher reduced to working at Valu-Mart, played with rumpled dignity by Tommy LaFitte.

The two young women are equally strong, the charismatic Brandi of Genna Styles and the haplessly uncharismatic Lainie of Kelly Marie McKenna, a whiner who gradually develops spine. The veteran Susan McGregor-Laine gives the prattling older woman a sympathetic hearing, and Bill Dalzell is deliciously brutish as the security guard who's not as dumb as he seems.

Why has "Valu-Mart" been controversial? Possibly because of raw language. Perhaps because of frank talk about race. And probably because a white playwright presumes to create black characters. Others may disagree, but they seem to me more fully actualized than the older white woman. Perhaps race is no harder a barrier to cross than those of gender or age.

In any case, drama carries us across all such barriers. "Valu-Mart" does so with entertaining energy, a perfect match for a theater company that has always mixed white and black with flair.

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