GO NO CHILD ... Many of us who didnt grow up wanting to be cowboys fantasized becoming one of those storied New York City teachers who make a difference. It was a vicarious dream lived out in books like The Blackboard Jungle or Up the Down Staircase and one we easily allowed ourselves to be talked out of by cooler heads. Actress Nilaja Sun didnt listen, however, and has toiled in the NYC school system for nine years as a teaching artist while working onstage and in TV. No Child ... is Suns spirited one-woman show about her classroom experiences, enjoying a run at the Kirk Douglas Theatre one year after its acclaimed off-Broadway premiere. It presents a roll call of frustrated characters who bring us face to face with a failed education system, while reawakening those long-ago dreams of making a difference.Sibyl Wickersheimers linoleum-tiled stage is cluttered with institutional chairs and set against a two-tone brick wall whose inhospitality is alleviated by two doors one to a closet, the other to the outside world. In the few minutes before the mornings first bell, you can almost smell the overripe bananas and apples left behind in lockers from the previous weekend. The first of Suns many characters is Baron the janitor an ancient storyteller who knows the history of this Bronx neighborhood and its school, once known as Robert Moses High School but since renamed for Malcolm X. Baron enters with a mop, singing Trouble in Mind, before describing the school and its two metal detectors, five guards and two NYPD cops.Heres Lesson No. 1, he says, with his own lesson plan in mind. Taking the 6 Train, in 18 minutes, you can go from 59th Street, one of the richest congressional districts in the nation, all the way up to Brook Avenue ... where Malcolm X High is, the poorest congressional district in the nation. In only 18 minutes.Its into the cauldron of Malcolm X High both an armed camp and a sea of raging hormones that Ms. Sun, a struggling actress behind in her rent, dives headlong. Her goal is to whip into shape the schools worst class of 10th-graders and, within six weeks, mount a play. And not, she replies in answer to her kids, A Raisin in the Sun or West Side Story, but Timberlake Wertenbakers Our Countrys Good, a story set in 18th-century Australia about a crew of convicts who stage a production of George Farquhars Restoration play The Recruiting Officer. It takes Ms. Sun a while to realize she was out of her mind to choose a work so ethnically distant from her kids milieu yet one that seems to draw an obvious line from prison life in Botany Bay to todays Bronx. But its too late, and the play-within-a-play-within-a-play becomes the thing.No Childs kids, only one of whom has had a brush with theater (a costumed re-enactment of Star Wars), are darlings but not angels; Ms. Sun, their acting instructor, must continually scold them for their racist impersonations of their English teacher, the Asian-American Miss Tam, and for calling each other niggers, bitches, motherfuckers and faggots.As Suns class becomes a little more civil and disciplined, she nevertheless begins hitting bumps as opening night approaches, often in the form of state tests required for federal funding under the No Child Left Behind Act. We spot the storys bad boy/natural leader early on in Jerome, a fatherless 18-year-old whos been marooned in the 10th grade for years. Although at first one of the students thinks theyre about to put on a play written by Justin Timberlake, the projects political implications soon dawn upon Jerome.Ay yo! Jerome shouts. This is some white shit. Aint this illegal to teach this white shit no mo? Like Anna Deavere Smith, Sun is good at mimicking the distinctive verbal tics of her characters, although it may take a moment or two for us to remember who she is at any given moment. Suns strength lies in an uncanny presentation of her characters body language, from the janitors ambling gait that suggests an old injury, to the imperious gestures of the Jamaican martinet who monitors a metal detector, to the precociously laid-back postures of her classrooms girls, such as Shondrika and Xiomara. Under Hal Brooks direction, Sun may never challenge our comfort zone (shes always our friend, and so were always on her side), but her narrator and characterizations never ingratiate. The one thing missing from Suns story is scenes depicting her students rehearsals, which wouldnt have added much running time to this fast, 65-minute evening but mightve allowed us to observe the kids tackling blocking and line readings while alluding to the greater theater of life outside school, with its own rules and language.No Child ... employs many of the tropes of stories about socially disadvantaged figures who become unlikely heroes, but Sun reinvigorates these characters to make them timeless rather than familiar. The result is a story that never becomes predictable. When Shondrika asks that eternal critics question, Whats this play about?, all we can guess is what it is not and thats a good thing. Tuesdays-Saturdays, 8 p.m.; Saturdays, 2 p.m. Starts: March 7. Continues through April 13, 2008