What does it really say about theater productions when, 99 times out of 100, they garner obligatory standing ovations, regardless of their merits (or lack thereof)? Absolutely nothing, of course.

But what does it say about a theater audience — especially on opening night, which is presumably attended by a company’s most loyal patrons — when, for the first time in my lengthy experience, roughly a quarter to a third of the people walk out at intermission on one of the best shows of the year? Considerably more, no doubt.

Georgia Ensemble Theatre's staging of the Eric Overmyer play "On the Verge, or: The Geography of Yearning" is not only one of the season's grandest efforts; it possibly qualifies as a singular achievement in the Roswell troupe's 24-year history — on an artistic par with such recent triumphs as "The Great Gatsby" or "The Elephant Man," and then some, because it isn't familiar material we've seen or read before, but instead a wholly unique undertaking that essentially comes out of nowhere to catch us by total surprise.

Thematically cerebral, stylistically imaginative and boldly original, “On the Verge” follows three 19th-century women explorers on a fantastical trek through an uncharted land they call Terra Incognita. Pith helmets in place, umbrellas and machetes at hand, by turns they find themselves in a jungle, or on a beach, or in a mountain range, never entirely sure where they’re heading or what’s in store. Neither are we.

Likewise, the play’s use of language is exceedingly verbose, to such a dense degree that a lot of it goes right over our heads, in that we aren’t always aware of what they’re talking about. Neither are they. Words and phrases will spring to mind that have no meaning to them (cream cheese), just as they happen upon artifacts that are completely foreign to them (an egg beater). It’s a good hour into the first act before it seems as if there could be a bit of “chronokinesis” involved, Overmyer’s euphemism for time travel.

To say much else would spoil the wonderment of it all. The beauty of how the plot thickens, though, is that the audience and the characters get to make certain discoveries and realizations in tandem. What may frustrate or intimidate some people — the ones who gave up and ran away at intermission — might strike others as a rather exhilarating reprieve from the usual mainstream, conventional, formulaic fare.

Exquisitely directed by the actress Carolyn Cook, the show is marvelously performed by its trio of co-stars: Park Krausen, as commanding as ever as the “social Darwinist,” Fanny Cranberry; Keena Redding Hunt, never better as the “liberal anthropologist,” Mary Baltimore; and newcomer Michelle Pokopac, delightful as the “lyrical polytopian,” Alexandra Cafuffle.

Talk about the “geography of yearning.” While “On the Verge” wouldn’t necessarily play any finer at an intown theater, it probably would’ve been more openly embraced there by audiences accustomed to thinking outside the box. Still, in the adventurous spirit of its heroines, kudos to Ensemble co-founders Robert and Anita Farley for taking the risk.

When Mary finally notes, “The future looks invigorating — quite promising, except, perhaps, for the theater, which threatens to degenerate into imitations of anthropological kinship studies,” it’s a genuine shame that those theatergoers who most need to hear that were already long gone.

THEATER REVIEW

“On the Verge, or: The Geography of Yearning”

Grade: A

Through Nov. 20. 7:30 p.m. Wednesdays; 8 p.m. Thursdays-Fridays; 4 and 8 p.m. Saturdays; 2:30 p.m. Sundays. $28.50-$37.50. Roswell Cultural Arts Center, 950 Forrest St., Roswell. 770-641-1260, www.get.org.

Bottom line: A rare thrill that deserves to be seen — from beginning to end.