Brown draws out the revelation of the ceremony that Sophie witnessed, trying to sustain his readers’ doubts about the fundamental goodness of the Priory of Sion. Everything else said about the organization, especially when contrasted with Opus Dei, makes its intentions seem honorable. But the fact that Sophie, a rational and educated person, could be so terrified and upset by what she witnessed suggests that perhaps not everything about the Priory is so upstanding.

Langdon can be timid. Despite increasing evidence that the police are not on his side, Langdon persists in wondering if he should have thrown himself on their mercy. His lack of intuition about the bad intentions of the police contrasts with his detailed knowledge of many other things in the world. He is a talented academic, but he lacks street smarts. Eventually, Langdon resigns himself to the chase and applies his intellect to uncovering the secret the Priory of Sion has been guarding.

Bishop Aringarosa is deeply conservative. He thinks the Church is now indulgent toward sin; he wants the Church to return to its punishment mode. He doesn’t think the Church should conform to the cultural norms of the time, and he believes that science is unnecessary. At the end of the chapter, when he pats his ring and thinks about how much power he will one day have, Aringarosa appears to be a tyrant-in-waiting, willing to ignore his own failings and shortcomings while judging others.

Fache’s affection for technology, as detailed in previous chapters, seems likely to lead him astray. Within the constructs of the novel, Sophie and Langdon are not merely a female cryptologist and a schoolteacher, as Fache snidely calls them, but instead a team prepared to elude the technological dragnet that he Fache is setting out for them.

By bringing the Holy Grail into the novel, Brown taps a longstanding interest in the ancient holy secret. Some readers may associate the Grail with Indiana Jones or Monty Python, but even if they don’t know anything about it beyond these vague associations, they are likely to be interested in the Priory’s secret.