The Primeval Archive
Although there are still signs it was once vibrant with scholarly activity, the library appears to have been utterly abandoned by all since ancient times.
The Party's Visit
The Party ventured inside at the behest of Lilli Longshadow, who told them that it housed a man once called Rochenion. She believed that he could be a "translator" who could help circumvent The Curse of Crossbones afflicting the party.
The group (and their companions) navigated the space with the help and guidance of a "ghost" who had fallen victim to the magical charm of Johann VonGruppen. Fighting some giant spiders and hooked horrors on the way, they managed quite quickly to find Rochenion's location, though not before they used a dead librarian's key to unlock a secret vault.
Inside a locked vault in one of the library's art galleries, the party found a painting that appeared to survive the aeons of decay that had consumed so much of the archive's innards. The painting depicted Odac standing serenely amid a field of destruction.
Attempting to remove the painting from the vault resulted in its immediate decay and corruption, and so the image was lost. Some books retrieved from the same room suffered an identical fate in Johann's backpack.
The Party found Roach magically sealed in a room beneath a swirling vortex of dust and debris, out of which books kept randomly falling. A message was carved in large letters into one of the walls, although some of it was apparently scratched away after the carving:
MY DEAR ROCH
SMILING AT LAST
The vortex that dominated the room appeared to have a maddening effect on those who walked beneath it. Considering that the onset of madness was all but instantaneous for members of The Party, it is inconceivable that even a shred of sanity remains to the drow-turned-nothic.