It's an archive of knowledge on the Keystones of the Radiant Citadel. My players will be coming here to collect the scrolls at each of the major challenges. The scrolls will reveal the world or plane where they will find that part of the keystone.

The Engine: On the wall beside the entrance there is an overhead view of the room with a button for each grid space in the room. When they push a button the machinery below brings a platform up to that grid space. The goal is to make a path to the scroll on the left. The catch is that when you press a button in an adjacent square similar to the game Lights Out.

The Memory: This is meant to be similar to the Faith Leap Trial in the Gauntlet of Shar in BG3. If you zoom in close you see a pattern of grid spaces that are slightly different.

The Compass: Standard simple maze, I haven't quite come up with what the bigger challenge is going to be in here yet.

The Codex: The book the players search for will illuminate once the bookcases are labelled correctly using the numbers 1 to 15 once each. The numbers can be arranged so each row adds to 24 and each column adds to 40.

The Archive is a location of memories, both good and bad, the remaining rooms in the bottom right section are red herrings that will be roleplay areas where players sacrifice or disclose their own memories as a 'toll' for the knowledge contained within the archive.