Remember the Olney Theatre? That sleepy little summer stock troupe in the woodsy outer reaches of Montgomery County, where actors performed in a quaint but impractical barnlike space with peach baskets over the lights?

It's grown up now. In fact, the 67-year-old company reached the end of a roughly 15-year adolescence Friday night as Gov. Robert L. Ehrlich helped cut the ribbon on a sparkling 429-seat theater where the equipment is new, the stage is bigger and the audience is closer. This is the end point -- or very near it (there is a parking lot yet to come, and perhaps even a restaurant on the substantial rural acreage that remains) -- of a long, steady period of growth. The original building has been patched up, a modest black box theater has become an integral part of the campus, and now the Olney Theatre Center has its own comfortable, fully modern, mid-size performance space.

Architecturally, the new building doesn't hold the aesthetic allure of some of the other recently opened theaters in the Washington area. The white structure is as simple and strictly functional as the Olney's quaint old barn, now known as the "historic mainstage." Inside, the high-ceilinged lobby that connects the old and new theaters handles the crowd adequately and lets in plenty of natural light, but in decorative terms it's surprisingly bland.

The performance space, though, is quite promising. It's a rectangle, like the historic mainstage, with a critical difference: Instead of placing the stage at one narrow end of the room with the seats receding as if down a slender runway, the stage occupies a broad side of the rectangle. This creates a wider and more flexible stage while keeping the audience at close range; seating is stadium style on two cozy levels.

And what's opening this spanking new space? William Gibson's "The Miracle Worker" -- which should perhaps be called "the historic 'Miracle Worker,' " because Artistic Director Jim Petosa and the core members of this cast did the show in the quaint old barn 13 years ago.

They make a thoroughly professional job of it, yet it's a curious choice for any number of reasons. Yes, Gibson's drama about the deaf and blind Helen Keller and her miracle-working tutor, Annie Sullivan, is an invitation to audiences of all ages, and bringing Carolyn Pasquantonio and MaryBeth Wise back in the same roles they played in 1992 as the young Keller and the indomitable Sullivan is a sweet nod to tradition. (So is the presence of longtime Olney actor and sometime director Halo Wines as the meddling Aunt Ev.) It's also a chance for Petosa and company to explore an untested space with a text they know well.

But it hardly says, "Look what we can do now," since they did it before, even if not with the intellectualized Gothic flair they bring to it this time around. Set designer James Kronzer strips the Kellers' country spread to stylized essentials -- a few stools and tables on an incongruously glossy black floor, a long ramp leading to oversize double doors at the back of the set and, of course, that crucial water pump at the lip of the stage. Intruding on this arrangement are tall floating panels of pipe and glass: angry, abstract mosaics suggesting the sensory-blocking obstacles walling Helen from the world.

Pei Lee costumes everyone but Helen in charcoal tones, and Daniel MacLean Wagner's lighting is spare and shadowy. It's the suppressed perspective of the blind and the haunted, as Sullivan -- once blind herself -- is tormented by the memory of the brother she left behind. Sensible as it is, the oppressive atmosphere is grim to watch, and it stifles the ripples of tough Irish-Catholic humor and stubborn hope that help keep Sullivan driving toward her goal.

In the end, "The Miracle Worker" is "The Miracle Worker" is "The Miracle Worker." It hinges on the strenuous battles and gradual breakthroughs between Helen and Annie. Regardless of approach (such as the one at Arena Stage a few years back with a sign-language chorus ringing the stage), the play rests in the hands of the two lead actresses -- often literally, given the urgent signing that goes on.

The acting in this case has been road tested, and for the most part it shows. Wise delivers an iron-clad Sullivan whose armor shows no cracks until very late in the play, though a bit of humanizing texture would be welcome in some of Sullivan's parries with Helen's parents. (James Slaughter is dutifully aristocratic and comically autocratic as Captain Keller, while Helen Hedman adds the required softer touches as the mother.) Pasquantonio, petite and nearly ageless, is a wanton flurry as Helen, eyes closed and hands flailing before her as the deaf and blind girl rages in the dark. Pasquantonio pushes the envelope in terms of being too old for the role, but she renders Helen's lively mind and fiery emotions with a fluid, energetic performance that's hard to second-guess.

Petosa gingerly explores the playing area, sending one actor to the floor by the front row and another up a ladder coming from a trap door, while Wagner shines discreet light on the cinder-block wall at the back of the stage (de rigueur when christening a new theater, it seems -- show the whole darn thing). Some of the experiments are rather conspicuous, but many of Petosa's stage pictures are lovely, and the moments of discovery between Helen and her dogged teacher are handled beautifully all around. As the emotion of the piece finally takes over, it becomes possible at last to stop thinking about the sheer fact of the new theater, and to begin to enjoy it.

The Miracle Worker, by William Gibson. Directed by Jim Petosa. Sound design, David McKeever. With Jermaine Crawford, Ashly Ruth Fishell, Max Rosenak, Chinasa Obugau, Christopher Yates. Through Sept. 11 at Olney Theatre Center, 2001 Olney-Sandy Spring Rd. Call 301-924-3400 or visit www.olneytheatre.org.

MaryBeth Wise, left, and Carolyn Pasquantonio in "The Miracle Worker."

Olney Theatre Center is inaugurating its new space with a play it featured in 1992 in its old space. Among the cast members in the current production are, from left in photo at right: James Slaughter as Captain Keller, Carolyn Pasquantonio as Helen, Helen Hedman as Kate Keller and Halo Wines as Aunt Ev.