About once a year the Bay Area gets treated to a magical theater gem that transcends time and genre, and this may be it. The latest main stage production at Berkeley Rep, running until Christmas week, is The White Snake, a beautifully executed and entertaining adaptation of an ancient Chinese legend directed by Mary Zimmerman in a co-production with the Oregon Shakespeare Festival, where it had its world premiere over the summer. Zimmerman has previously brought several similarly inventive adaptations to the Berkeley stage including 1999's Metamorphoses (for which she won a 2002 Tony Award for the Broadway production), and 2008's The Arabian Nights. And just as before, with The White Snake, she culls beautiful vignettes and powerful emotional truths out of an old text without it ever feeling arch, or anachronistic.

Zimmerman likes to do her writing in the midst of the rehearsal process, finding individual moments and dialogue in collaboration with her actors. But this story was a particularly mutable one, with different characters, themes, threads, and outcomes added and subtracted to the tale over the centuries. The narrative she lands upon embraces the different threads, treating them like crossroads to be described to the audience at various points in the tight hour-and-forty-minute show. With each actor in the ensemble narrating different pieces of the story, we're treated to several alternate versions along the way, with the conclusion, at each crossroads, that both are equally interesting and worth telling.

The basic plot goes like this: a female white snake, living atop a mountain beside Buddhist monks and herself learning Buddhist dharma over thousands of years, decides one day to descend the mountain and live among humans. Having studied so long, she is able to easily change her own shape and become human, at least temporarily, and she ends up falling in love with a pharmacist and getting pregnant with his baby. Meanwhile, an evil monk, believing she is defying nature, sets out to expose her and remove her from the human realm.

Zimmerman's adapatation is elegant and at times hilarious, with the help of great and funny performances by Amy Kim Waschke as the White Snake; Jack Willis as the monk, Fa Hai; Christopher Livingston as the affable and gullible Xu Xian, the pharmacist; and Tanya Thai McBride as the scrappy and impulsive Green Snake who serves as the White Snake's friend and protector. Everyone speaks in plain, modern English and is accompanied by a small band, and a bevy of low-tech and lovely visuals — from parachute fabric masquerading as clouds, to a single, round paper lantern carried across the upstage ever so slowly to represent the full moon over the course of a night.

The tale grows more complicated toward the end, and gets all the more interesting through our modern lens. Where at certain points in China's cultural history it took on the conflict between religious faith and duty to marriage and family, it's hard not to hear parallel arguments against gay marriage coming through in the rhetoric about the "unnatural" union of this snake-woman and her beloved husband, and her sincere desire to lead a "normal" human life.

Mara Blumenfeld's costumes shine terrifically on the spare set by designer Daniel Ostling, with the actors, their clothes, subtle lighting, and a few simple set pieces creating tableaus as striking as Chinese ink drawings. It's a play that will leave you feeling warmed and transported, and reaffirm your faith in the power of storytelling on a stage.

The White Snake plays through December 23 at Berkeley Rep. Tickets here, and if you're under 30 you can always get 1/2 price tickets, with proof of age required at pickup.