Can you be a little bit more clear on who knows everything?
Viewing post in The Mysterious Gear Chest walkthrough comments
If you're talking about my notes in the walkthrough well, ** SPOILER ** there are at least three characters - two because they were there when the thing started around 400 a.C. - but they won't help (one because has been trapped by a faction, one because he signed a pact and fears the consequences about breaking it) - but the one you need to talk to (because he has the almost-final piece missing) he's the one who stripped the chapter about Chako **fifty years ago** - he knows everything about the Gear Chest - and acted other time during his life to protect the seals.
This is the long version
The short one is that is the Rector who knows everything BUT the current situation (the one you saw in the prologue)
Ask me more if I didn't answer your question
to close it you need a SECOND golden key that you can have from the Rector - asking him what he still need to know to be helped
if he doesn't still help you you may have not yet discovered that there's a golden statuette on the ISS - that you learn from Samuele (thru Andrea) if Andrea asks him about Tarrisi - knowing that Marco can correct the Rector when he says everything is still find and then he will help
I'll check it (to see if there's not an error somewhere) but this should be the correct sequence
I hope this is the missing detail