Most people know Kenneth Lonergan for his moving, Oscar-nominated screenplay about the complexity of sibling relations, You Can Count on Me. But the newly noted writer has also penned several pieces for the stage, including the coming-of-age drama This Is Our Youth. Like his film, Youth exhibits Lonergan's rare knack for creating introspective story lines revealed by in-depth characters and raw, rhythmic dialogue. The two-act play takes place on New York's Upper West Side over the course of one weekend in 1982, when three post-high school kids -- raised by progressive, nouveaux-riches parents with hippie ideals -- realize they are stuck in the limbo between childhood and adulthood. Warren Straub (Christian Haines) gets thrown out, again, by his violent father, and then steals $15,000 from him. Warren's only friend, Dennis Zeigler (Elijah Berlow), takes Warren in, but then uses him to vent his anger toward his own parents. Jessica Goldman (sassy redhead Lauren English) and her argumentative intellect -- not to mention booty potential -- leave Warren smitten and dumbfounded. The three struggle to iron out the creases of their oncoming maturity by spouting pot-induced philosophical theories, but the usual adolescent suspects -- hard drugs, confusing sex, and "Why me?" anger -- get in the way of their achieving real clarity. It's a superbly written piece of work, and Paul D'Addario's heartfelt, organic direction elicits unpretentious performances from the talented cast. The chemistry between Haines and English sizzles like a live wire. Jen Welch's costume design is a hoot, shooting us straight back to that unforgettable Reagan era of Izod sweaters, Chinese slippers, bangle bracelets, and (ouch) crimped hair. It's true that Youth is essentially about rich kids, but it's also about that painful moment most Americans experience when what once seemed like the eternal truth gets exposed as a candy-coated mirage -- for better or for worse.