Human librarians, or "not every human is visually, vocally, or physically intimidating...or needs to be to be fearsome." -- Anon Guest
[AN: Have you met any librarians, Nonny? They only appear soft and weak. They lift tomes on the daily, have a vast knowledge of nearly everything, and a supernatural ability to put up with seventeen different kinds of horseshit at once. They are therefore minor gods.]
In a world of ignorance, a knowledgeable person is either king or crazy. In a world of disasters, a knowledgeable person can rise from the latter to become close to the former. Sometimes, both can happen at once.
Never mind what apocalypse occurred to lay this particular world - or part thereof - to waste. There are plenty to go around. Famine, disease, war, all of the above and the environment striking back against the slings and arrows of outrageously overblown industry... Or your generic judgment from an otherwise uninvolved deity. Take your pick. What's important is that the central structures have collapsed, and all the might-is-right, survival-of-the-fittest numbskulls have come out in force to attempt to predate upon the weak.
Like so many wannabe barbarians angry at institutions for ruling them and science for confusing them with facts, they sought out the edifices of both. The former seats of law and government quickly fell, but the libraries... The libraries were defended.