It all depends on whom you believe, says, CBS Sunday Morning contributor Martha Teichner.
"In the book, Opus Dei is in some sense the villain of the piece. A dark, menacing cult that dispatches albino monks to slay its enemies. It practices extreme forms of self-flagellation and unthinking obedience to superiors," says John Allen, Vatican correspondent for the National Catholic Reporter.
He's written what is widely considered the definitive book on Opus Dei.
"There's the Opus Dei of myth which is the Opus Dei of Dan Brown's 'The Da Vinci Code.' Then there's the Opus Dei of reality which is a relatively small group of about 85,000 Catholics worldwide, who are committed to what their founder, a Spanish saint by the name of Jose Maria Escriva called the sanctification of work," Allen explains.
Escriva founded Opus Dei -- Latin for the "work of God" -- in 1928 in Spain. He taught that through any kind of honest work in the everyday world, ordinary people, striving for a kind of spiritual perfectionism, can find holiness.
There are priests in Opus Dei, but they're only 2 percent of the total membership. Seventy percent are lay Catholics, called supernumeraries, who live at home with their spouses and children. The rest, called numeraries, live celibate lives in separate men's and women's Opus Dei residences, but tend to work outside. In "The Da Vinci Code," Silas is a numerary.
In real life, so is Susan Mangels.
"When somebody chooses to make a lifetime commitment to Opus Dei, you can choose a ring of your choice to wear," Mangels tells Teichner.
Mangels was actually engaged when she decided that Opus Dei, not marriage, was her vocation.
Susan Mangels is president of Lexington College in Chicago, an Opus Dei-run women's school that teaches the culinary arts.
Opus Dei points to Mangels as proof that its members aren't weird and to the college as proof that its intentions are good.
Likewise Father Hillary Mahany, an Opus Dei priest at Saint Mary of the Angels church in Chicago's Bucktown neighborhood.
"Well I think the city had condemned the building," Mahany says of the church.
It was in that condition in 1991, when the Chicago Archdiocese turned it over to Opus Dei and said, "Here, you save it." Now it's the only fully Opus Dei staffed church in the United States.
Mahany says it took four years to restore the church and now, see it as a source of stability in the neighborhood.