Found: Sci-Fi/Dystopia/Horror/Adventure novel published in '00s, I think.

A lot of the details are hazy, but what I do remember is that it's basically about a group's epic trek into the heart of Africa to find this hidden colony of very old vampires, living in a very old and massive impact crater, for their help in saving the world. Oh, and civilization is teetering on the verge of collapse because of... well, other hordes of evil vampires.

An almost ridiculous-sounding plot, I know, but I was so into it! It's well-written, but I draw a complete blank when I try to remember the author's name or the novel's title. Google has been no help, so any help from you, good people, would be much appreciated.

Thanks.

The Passage? It starts with a scientific expedition to (IIRC) find the site of a plane crash in a jungle, survivors of which have become strangely immune to disease. Things escalate from there.

It's been 30 years since I read them, and they're from a decade earlier than you suggest, but parts of this align with what I remember from the early books in the Anno Dracula series by Kim Newman. Probably the first book if my memory is correct. Like I said, the series started in the 90s, but you might have encountered a rerelease timed with one of the later books.

If there's a time travelling train involved, it's Aldiss Dracula Unbound

I don't think it's any of the suggestions above. I appreciate the feedback, though. The only other person, I know, who's read it can't remember either, but now they're doing some digging, as well.

Could it be something by Brian Lumley?

Hey, hey, hey, my friend did his homework & figured it out!! It's 'Empire Of Fear' by Brian Stableford. It was published in '93... I was off by a decade. So, I can add it to my faves now.

Thanks a ton for all of y'all's suggestions. This is a great forum... seems to be very positive, which, I gotta say, in today's world means everything.

touchstone: Empire of Fear by Brian Stableford