For the past four months, scores of Americans who seldom, if ever, darken the portals of a theater in their homeland have been crossing the Atlantic to run a theatrical gauntlet. These tour-package pilgrims are heading for an audience endurance test in Oberammergau, Germany, comparable in its own way to the ordeal of the New York City Marathon. It's the 40th season of the world-famous Passion play, a seven-hour drama, mounted by citizens of this Bavarian village once a decade (more or less) for the past 366 years.

Hard as it is to fathom, approximately half of Oberammergau's population of 5,200 is performing in this year's version--and more than 500,000 people from around the world are attending the play and a related exhibition by American avant-garde artist Robert Wilson that depicts the Stations of the Cross. Cognizant that this opportunity comes but seven or eight times in even the longest human life span, the tourists are paying homage to a tradition shrouded in myth and hokum. James Shapiro's compelling critical account, Oberammergau: The Troubling Story of the World's Most Famous Passion Play (Pantheon, $24.00, 239 pages), has been published to coincide with the five-month season of the play. Relatively few of Oberammergau's tourists are likely to read it--but what an eye-opener for them if they should!

During the Middle Ages, modern European theater evolved from liturgical reenactments of Bible stories. Once upon a time, hundreds of communities, as well as craft and trade guilds, in England and on the Continent sponsored Passion plays and other religious dramas. Only the Oberammergau production has survived as a continuous operation, a curious vestige of Medieval culture. According to legend, this municipal tradition began with a 17th century vow by the town's citizens that, if God spared them from the plague, they and their heirs would produce a pageant about the crucifixion and resurrection of Jesus. Decade after decade, the picturesque Passionsdorf (or "Passion village") gloried complacently in its prestige as the site of a world-renowned tourist attraction and exporter of quaint wood carvings. Through all those years the Oberammergau drama, drawing on the Gospel of John, portrayed Jesus as a victim of villainous Jews.

While Oberammergau followed its drowsy, Brigadoonesque routine through most of the 20th century, the rest of the world was being transformed by wars and ideological revolutions. The ecumenism of the Second Vatican Council, the revelations of contemporary scholarship regarding first-century Judaism and the historical Jesus, and--most of all--burgeoning awareness of the brutality of the Holocaust led to critical, often hostile reactions for the Oberammergau pageant. Since Vatican II, theologians have sided with special interest groups such as the Anti-Defamation League of B'nai B'rith, disavowing the tradition that demonizes the Sanhedrin and resisting the notion that Christianity, as a "new covenant," supersedes Judaism. Today Oberammergau is still trying to live down the taint of Hitler's enthusiastic visits to its Passion play and to address continuing charges that the script, though much revised in the latter part of the 20th century, is philosophically repugnant. The producers of the play are experimenting with dramatic conflicts that don't involve Jewish scoundrels, determined to make their text both politically correct and theatrically viable.

Shapiro, who teaches English and comparative literature at Columbia University, was in Oberammergau last year for the beginning of the seven-month rehearsal period. The author, who previously published Shakespeare and the Jews, is frank about his prejudices. Having "grown up in the 1960s in a Jewish home where one didn't buy German, speak German, or visit Germany," he admits starting his research with the gravest skepticism about what he would find backstage at the Passion play. "Without saying it in so many words," he writes, "I believed in collective German guilt, a guilt that fell not only on those who had lived through the war, but also upon their children and their children's children. The irony that this reflexive notion of collective guilt was precisely what I found most objectionable in the Passion play (with regard to the Jews who called for Jesus' death) was not lost on me. One of the things I hoped to learn in Oberammergau was when, if ever, would it be time to bury this notion of collective guilt."

In Oberammergau, Shapiro stretches beyond his own academic field to blend historical, theatrical, and theological research with a lively personal report of what he saw, heard, and felt during the planning period and early rehearsals. He doesn't leave room for illusions about the village's past anti-Semitism (as well as other unsavory aspects of its history). But he's emphatic that, while spending time with the town's elders, the stage director, actors, designers, and those revising the script, he "developed a great deal of respect for the integrity of everyone involved." Seeing the play's cast struggle with "the message of a Jewish Jesus and his followers," Shapiro says, has convinced him that the theater is "one of the most powerful ways of changing the way people think, and not just audiences, but actors, too."

Although Shapiro earns his living as an academic, this interdisciplinary study is rendered in vigorous prose, refreshingly free of contemporary English department theory and argot. Because the manuscript was put to bed long before the premiere of this season's Passion play, and even before rehearsals were in full swing, there's a truncated quality to the book. It's easy to understand Shapiro's publisher wanting to rush into print to take advantage of the 2000 season. But waiting to include an account of the events of the summer and this fall, along with an analysis of who attends and their responses, would have meant a far stronger, more thorough treatment of the topic and a more satisfying book.

Few of the Passion play's American spectators, one guesses, are likely to care how this remnant of Medieval drama relates to European history or what ideological forces have clashed over the ancient prejudices the play embodies. To the extent the American tourists hope to find in Bavaria a religious Orlando, visually stimulating and intellectually unchallenging, they'd better avoid Shapiro's book, guaranteed as it is to dispel the romantic haze of the travel brochures. Those willing to engage Shapiro's ideas, however, have a chance to reach with him across an inexcusable gulf that has separated Jews and Christians for far too long.