Just mentioning another campaign that ties into this infinite library theme. Dahlia’s Diversions for Peculiar Parties by Steven Jackson Games (a current backer kit project) is a set of eight short RPG games. One of them is called Overdue. “Overdue is a GM-less game of magical research for up to four players. You are an apprentice librarian at the Central Branch of the Omnifold Library, entrusted with an important and hazardous duty – you must retrieve one of the library’s overdue books. Of course, those books tend to be checked out by powerful wizards, so you’ll need to make sure your grimoire is filled with spells for any contingency. You may learn something surprising along the way! This game is a treat for library lovers, occultists, and fans of the classic game Exquisite Corpse. Designed by Ash Cheshire. Illustrated by Ben Williams.” I am in no way affiliated with the project/campaign. I thought people might enjoy adding to their Librarian’s Apprentice thematics.