Pope John Paul II's latest memoirs, "Rise, Let Us Be On Our Way," may have topped Italy's bestseller list in 2004, but by the end of the year, many Italians were reading a decidedly different book: "Angels and Demons."
The novel - released here last month - is classic Dan Brown: Like his better-known blockbuster, "The Da Vinci Code," this earlier work follows the adventures of Harvard symbologist Robert Langdon - accompanied, of course, by an erudite and beautiful female scientist - as he uses historical clues hidden within Renaissance art to unravel a murder mystery.
Fans have flocked here to retrace Langdon's architectural scavenger hunt. Several tour companies now offer "Angels and Demons" tours.
But where "The Da Vinci Code" may be unflattering to the Catholic church, some Catholics consider "Angels and Demons" insulting. Its tale of a warped mind desperate to save the faith takes Mr. Brown's challenge right to the Vatican's door.
For fervent Catholics, Brown's success is the latest evidence that anti-Catholicism is not merely, in the words of US religious historian Philip Jenkins, "the last acceptable prejudice." It is fashionable.
"Catholics have to put up with all sorts of abuse that would be considered outrageous if targeted at any other religion," said lawyer Gianluca Bacchi, leaving the church of Santa Maria in Trastevere after mass this week. "The Catholic Church is depicted as not just old-fashioned and out of touch but amoral, power hungry, and sexually perverse."
Dan Brown has denied that "Angels and Demons" is "antireligious or anti-Catholic." But some readers say that his sensational conspiracy theories could intensify the anti-Catholicism that has swept Europe in recent years.
The plot details an attempt to destroy the Vatican with an antimatter bomb and contains disturbing images of naked cardinals murdered in Roman churches, Swiss guards bundling bodies into car trunks, and a poisoned pope who turns out to have fathered a test-tube baby.
Some art historians and theologians have criticized Brown's text for containing historical inaccuracies.
Still, Italians cannot put Brown's book down. Its racy, detective-thriller tones and descriptions of the inner workings of the headquarters of the Roman Catholic church offer a compelling window into the world's smallest - and most secretive - country: Vatican City.
Many of Dan Brown's greatest fans are in fact loyal - if not practicing - Italian Catholics who, while aware of the fictional aspects of 'Angels and Demons," appreciate it for raising questions about their faith that Catholics writers tend to avoid.
Archbishop John Foley, US-born chief of the pontifical council for communication and culture, says "The Da Vinci Code" is "blasphemous" and "insidious."
"It's interesting, but I was a history major and I could punch holes all over it," he says in an interview in his Vatican offices. Despite Brown's record sales worldwide, Foley says, the pope has "too much on his plate" to read his books.
But the arrival of "Angels and Demons" in Italy makes it harder for the Holy See to ignore.
The Vatican's antiabortion stance, its skepticism that condoms can help prevent the spread of HIV/AIDS, and its opposition to scientific research on embryos have added to a widespread belief among liberal Europeans that the Catholic church is old-fashioned, out of touch, and fair game for the critics.
European Catholics have expressed mixed feelings about Brown's books.
Civilta Cattolica, the Jesuit periodical, has condemned "The Da Vinci Code" as a "a thriller with an engaging plot" that is full of "breathtaking absurdities." Spanish Catholic church representatives have warned that Brown's books are "seductive." And the Catholic Church in Lebanon has banned the book.
The Vatican has refrained from formally criticizing Brown for fear of contributing to his success. "We've done away with the index of forbidden books," says Foley, noting that Mel Gibson's film "The Passion of Christ" became all the more popular when the Anti-Defamation League condemned it as anti-Semitic.
"Those who criticize this book too bitterly are forgetting that it is just a thriller," writes Roberta on an Italian internet discussion page.