As she traveled with playwright Tadeusz Slobadzianek through the Czech Republic and Poland last summer, Blanka Zizka, founding director of the Wilma Theater, noticed that many of the towns they passed through were full of vivid posters advertising theater, concerts, and other activities. But their destination, Jedwabne - on which Slobadzianek modeled the town in his play Our Class, whose central event is the 1941 massacre of its Jews - impressed her only with the vacuity of its cultural life.

"What I found important," Zizka says, "was to be able to inhale the same air, to see the landscape, the surprising flatness of it, the misery of the small places, the void of the Jewish presence, the overgrown Jewish graveyards . . . ."

Our Class, now in previews, opens its U.S.-premiere production Wednesday night at the Wilma, with Zizka directing Ryan Craig's English version.

The play's first act fictionalizes real events through the eyes of 10 schoolchildren, from the 1920s to the July day in 1941 when Jedwabne's Jews were forced into a barn that was then burned to the ground. The second half follows the survivors in post-wartime through the turn of this century.

The play, like the 2001 history book that inspired it, Jan Gross' Neighbors, has generated controversy since it premiered in London in 2009. In Poland, it has run continuously since 2010.

Jedwabne (yed-vab-nay) could be any town in eastern Poland during World War II and so is never mentioned by name in the play, which centers on the lives of the 10 classmates who represent the townspeople - five Catholics and five Jews - who initially are friends, more or less, until nationalist rumblings begin in the 1930s, and then first Soviet and later German forces sweep in.

Over the course of 80 years, they - or their ghosts - struggle with one another and then with the memories of what takes place. They change or they don't change: hero, victim, villain, rescuer, murderer, watcher, enabler. Classmates. Neighbors.

According to Gross' study of Polish, Soviet, German, and Jewish census and trial records, 1,600 Jews lived in Jedwabne at the time of the massacre, which occurred just weeks after the Germans had pushed out the Soviet occupiers but before they arrived in full force.

Based on Soviet court documents, Gross concluded that on the eve of July 10, 1941, the town council and the few Germans already there "agreed to the murder of the Jedwabne Jews." The next day, with help from men who arrived from towns nearby, Catholics rounded up the Jews and herded them into the barn to die. The Germans were not in charge of the day's events, as had long been assumed. The Poles were.

"A historian can't do what a play can do in taking it to the public," Gross told the audience at a Sept. 18 talk at the Wilma, where he also spent two hours with the cast of Our Class. The Wilma team has immersed itself in the play's time. It saw the Agnieszka Arnold documentary Neighbors, from which Gross took his book's title, and last spring went to Toronto's Studio 180 to see a production of the play there.

 For Zizka, something more was required.

"Whenever I direct a new play," she explains, "Walter [Bilderback, the Wilma's dramaturge] and I do lots of research on the background and the playwright, but there is nothing better than meeting the playwright in person." So she and Slobadzianek met just before she saw Our Class in Warsaw.

On seeing it, she says, "I knew I wanted to stick to my preconceived ideas about how I wanted to direct it. I'm thinking more of a kind of a soul or a memory bank. The light inside the barn, or what we're calling the glass house, will come spilling out like the memories . . . ."

It was Bilderback who had brought the play to Zizka's attention, and who initially interviewed Slobadzianek. "Reading the texts by Jan Gross, and Anna Bikont's We From Jedwabne, I clutched my head," he says. "I realized it wasn't that some 'they' got rid of 'the others.' "

Our Class lasts three hours. "I would love to do the play without intermission," says Zizka, "but I think it's impossible for the sake of the actors. The play is riveting. I have nine Philadelphia actors and one, Michael Rubenfeld, who was in the Toronto production. He said even the high school students who saw the play were gripped by it. We are working right now with South Philly High, the problems between Asians and blacks there, so these themes have been repeated over and over.

"I didn't realize how dramatic the second half is until I started to work on it," she says. "It's a moral navigation through what has been done and how to deal with it. I was a little bit afraid. How can we find the truth in the memory of these 10 people and their different ways of remembering?"

The play tests the younger actors who have to portray complex characters. Rubenfeld, who played Abram in Toronto, has the most experience with it. "The stage here at the Wilma is bigger, so the production has a particular quality of expansiveness. I'm finding Abram's guts here. Blanka is pushing me to let loose."

Krista Apple plays Zocha, a Polish woman who hides her friend Menachem, saving his life. "She's very different by the end," Apple says. Settled into a comfortable life in the United States, Zocha "returns to Jedwabne 60 years later, and she's moving on in a very profound way." Apple's trepidation about the role came through "the desire to do justice to the truth of these people's lives."

Another character, Dora, is gang-raped and then must admit she found pleasure in it. How does 23-year-old Emilie Krause grope her way through that labyrinth? "The prerehearsal vocal and physical exercises we practiced with Jean-Rene Toussant in workshops this summer free us up to go to magical and horrible places," she said. "My research revealed that under heightened circumstances the body has many ways of defending itself, including choosing to feel pleasure over pain."

Ultimately, says Zizka, playwright Slobadzianek "is talking about how choices, necessity and destiny, living next to each other, are creating the story of life, and I think that is so beautifully captured in the play. I really don't feel like we are doing a historical play. We are doing a play about relationships that can go bad."