The Da Vinci Code Made Them Famous. But the Truth Is Way Scarier Than Fiction.

Opus Dei emerged from fascist Spain through a close alliance with the Franco regime.

British journalist Gareth Gore 's book Opus: The Cult of Dark Money, Human Trafficking , and Right-Wing Conspiracy Inside the Catholic Church .

Gore describes financial crimes, sexual abuse, the grooming and coercion of recruits, the drugging of members, human trafficking, and even slavery.

Opus Dei is riddled with abuse, manipulation, and militant politicization, says Dan Brown .

Brown found documents in the bank's archive that detailed where the money from the bank had gone, including to a school in Argentina where teenagers had been coerced into a life of servitude.

Brown: "This is just the tip of the iceberg. I think this is going to be the next big church scandal".

Opus Dei has 3,000 members in the U.S. but its largest community is in Washington , D.C. , says John Avlon .

Avlon: Opus is a network of like-minded archconservative radicals who use beliefs to push forward a deeply political agenda.

He says many of the Washington political and judicial elite are tied to the organization in some way, including Supreme Court Justice Antonin Scalia .