I like how they fall behind the shelf, never to be seen again until renovations years in the future... At first the library will think "wow this is selling great, Put more on the shelf". Then the maths wont add up with the till numbers and a dawning will wash over as the thought of "Oh No, These were stollen", Slowly the mind churns as the librarian attempts to process this situation, "Who would steal such a book?" In time, She will have a realization and wake up. Or not.