how does that work though? Obviously you gotta unlock the final page to get that knowledge I'll wager?
Yep. You have Astarion fully unlock the book once you figure out how to do it (in Act III). You get another cutscene and he'll talk about what he found in it.
I believe I recall asking him about the book once it was fully unlocked and him briefly mentioning the ritual yeah (cause in all my runs I did Raphael's request).
