BreOl72: I mean: it's not like this kind of inconsistent naming is something new...
timppu: Do those books have anything else in common than the protagonist and the catholic church? A bit like James Bond movies/books, or the Remo books (yay! They were the most bestest!)
It's been a while, since I read them.
I think there may be a few back references to older books, but no - nothing like an "overarching story arc".
The books as such are simply always about the same guy
(Robert Langdon), who stumbles into a new mystery
(in a new city/country) with each book.
There's nothing really "connecting" the stories.
But if someone starts with, say, "Inferno", they may read a sentence that refers back to "Angels & Demons" or "The Da Vinci Code".
I don't know
(or rather: haven't played) the three games mentioned above, so I don't know, whether their stories are more intertwined.
I read MarcoH01's post as "the three stories are independent from each other, but there's a story arc in the background, that unites them."
Without having played them, that could mean anything, as far as I'm concerned.
Could mean: "connected like the "Gabriel Knight" games are connected".
Those three games each have an independent story, the only "overarching connection" would be, that Gabriel Knight is the "Shadow Hunter", and as such involved in three different mysteries.