Wellll... It was caused by this guy named Loki. He's actually kind of like a spirit! Of mischief and stone. But he looks like a person, not a bird. But... that's beside the point!

The thing is, he said he could let you enter the library. But... he also wants you to not have strict rules over it, a-and to announce it. So you won't be able to stop people from taking books out or ban them...