Filming of "The Da Vinci Code," starring Tom Hanks and Audrey Tatou, is well under way all across Europe -- but not all the attention is from paparazzi and fans.
In England this week, Sister Mary Michael, a 61-year-old Roman Catholic nun, prayed for 12 hours in protest outside historic Lincoln Cathedral.
That's where Hanks and director Ron Howard were shooting the adaptation of a novel whose plot questions much of Christian theology, proposing that Jesus and Mary Magdalene were married and had a child.
"When I die," Sister Mary Michael said, "and I have to stand before almighty God -- as everyone else will, whether they believe it or not -- and he says to me, 'What have you done to defend me?' I can say, 'Well, I tried to come forward at Lincoln Cathedral.' "
She's not the only one coming forward.
The scene was shot at Lincoln Cathedral rather than Westminster Abbey because Abbey officials refused the filmmakers' request to use their site. They cited the book's "contentious and wayward religious and historic suggestions." So film crews at Lincoln Cathderal re-created Westminster's elaborate screen, the altar, and the grave of Isaac Newton.
Lincoln officials decided it was worth the increased tourism, not to mention a reported donation of 100,000 British pounds (almost $180,000) from the makers of the film.
"It's given us an opportunity to talk to people about 'The Da Vinci Code,' about Westminster Abbey and about Lincoln, and sometimes about the faith that we represent," said John Campbell, an official at Lincoln Cathedral.
It all illustrates what seems an impossible challenge for the filmmakers.
"The Da Vinci Code" has two notable characteristics -- record-breaking sales of more than 25 million books worldwide in 44 languages, and a plot that has been decried by Catholic leaders as heretical.
"It could popularize even further certain distortions of the Christian faith which we think appear in the book," said Monsignor Frank Maniscsalco of the United States Conference of Catholic Bishops. Those include "the fallacies about Jesus' life, questions over his divinity, that he has descendants."
Christian groups, including the United States Conference of Catholic Bishops, have registered protests with Sony Pictures, the studio making the film. The protesters also include the conservative Catholic sect Opus Dei, portrayed in the book as a bunch of thugs.
So despite the combination of Hanks and Howard, and an almost preposterously successful novel by Dan Brown, the movie is something of a risk.
"In a perfect world, Ron Howard wants to be able to have Dan Brown enthusiastic and to have Pope Benedict enthusiastic," said Michael Medved, the film critic and conservative commentator. "You can't please both of them."
Since the controversy erupted days ago, filmmakers instructed the Rev. Richard P. McBrien, a theology professor at Notre Dame University and a consultant to the film, not to talk to the press. But ABC News spoke with him in March.
"The bottom line is it is a novel," McBrien said. "It is a work of fiction. It isn't a work of history. And for the Vatican or for an archbishop or anyone else to get all upset and excited about it, seems to me, is an excessive reaction."
It is a work of fiction. But religious officials worry readers -- and soon viewers -- will take it as seriously as author Brown seems to.