"I don't know, it seems like forbidden knowledge might be forbidden for a reason."

"It might be, though possibly just 'it's arcane and dates back to Sarkoris' would suffice to explain that. Perhaps you can say why it's forbidden?" he asks the ghost.

"Simple puzzle, simple solution. The Heart of Mystery is located west of here," the ghost says, as if this was a remotely helpful answer.

Sigh. "If everyone's amenable we can proceed to the next room of the dungeon."

"I suppose if ghost boy is uninterested in answering further questions that is our best prospect of finding answers in this location."

"Plus, maybe the next room will have some actual loot!"

"That would certainly be nice." What's in there.

Weird-looking spider murals! Several chests!

(The ghost vanishes, leaving the map behind.)

"The outsides of the chests aren't magical but the insides are blocked for me."

"I don't see any traps, either, am I good to open them?"

"One at a time in case something surprises us but be my guest."

He opens the first one.

"...Anyone here read Elven?"

"Me!"

He hands her a stack of loose papers. "There's also some spell diagrams, that's just math, and some potions. I dunno if potions go bad after a thousand years. And the whole thing's lined with... probably lead, if it blocked your Detect."

"...I can usually read Elven but this Elven is different somehow."

"Like it might be in code or like it's ancient?"

"...Both, I think?"

"The paper's magic, I think to stop it decaying. So are the potions."

"I don't have a Comprehend today and even if I had it wouldn't work on code..."

"Perhaps we will be able to make more progress tomorrow."

"Do your magic thingamajigs work?" She taps her left wrist.

"His what?"

"You were the one who asked me to help test them! They do translation." Sigh. "You'd better hope those notes you're always taking mention them, you spent so long dragging people around the tavern..."

"I assume they're based on magics that are meant for languages and not codes, but -" He peeks.

Much of the writing is indeed enciphered, and as expected his translation magic is unhelpful.

But not all of it. 

He's looking at some kind of journal, that's clear enough from just the parts written plainly. The dates are written by reference to some elven calendar Blai's never heard of, but there are scattered references to the perpetual darkness blanketing the planet, to the recent deaths of the moon and her lover, to the flight of the author's fellow elves. Throughout the pages, the author regularly switches to cipher for individual paragraphs, sometimes individual sentences. But towards the end, there's a reference, unenciphered, to the idea of staving off the planet's starvation with a portal to the Summerlands or to the bountiful forests of Nirvana or Elysium, and everything afterwards is in code.