(Is this a Bug?) Shalidor's Library Books Disappear before being Found

Sword_Artist

I have the Lorebooks Addon that tells me where all the Shalidor's Library books are on my map. Sometimes, when I read a book, other unread books nearby disappear from my map tracker. At first I thought this was a bug with the addon, but then I went to a location that previously had an unread book marker, and the book really was gone without my reading it. Is this a glitch or part of the game? Do we only need to find a certain number of books in a region that is less than the total number available?

Enodoc

There are a number of books that appear in more than one location in a zone. If you find one copy of the book, the other copies disappear.

Ranique

most books have several copies on the map. Typically clustered close to eachother. In the addon this is indicated by a simular mapicon. Once you have read one, all of them dissapear, but they are identical and would have counted only once anyways.

Sword_Artist

Thanks for the help!