Conspiracy, secret society, Epstein parallels

I have read Foucault's Pendulum and some Robert Anton Wilson. What I'm looking for is something that seemed like an outlandish fiction, but in light of the Epstein files, just doesn't seem so far-fetched. Eyes Wide Shut vibes. A fictional story of coming close enough to the unseen world to get a glimpse. I've read every Dan Brown but that is very close as well.

I'm also wondering if the dark reality is too dark for a fictional take. Pedophilia, blood sacrifice, torture, cannibilism… Maybe this isn't content I should locate. What have you got to suggest or caution?