The three rules of the Librarians of Time and Space are: 1) Silence; 2) Books must be returned no later than the last date shown; and 3) Do not interfere with the nature of causality.

There are some laws that are coded into the very nature of the universe, and one is: There Is Never Enough Shelf Space.

Time and space were, from Death's point of view, merely things that he'd heard described. When it came to Death, they ticked the box marked Not Applicable. It might help to think of the universe as a rubber sheet, or perhaps not.

Too much magic could wrap time and space around itself, and that wasn't good news for the kind of person who had grown used to things like effects following things like causes.