And if you venture far enough into the stacks - far enough that wood and brass give way to brushed aluminium, and then to wrought iron and stonework - far enough that the mass of accumulated knowledge bends the fabric of reality like weights on a rubber sheet - you may find yourself in the places where past and future, fact and fiction, here and there become one. In those liminal spaces, there are three rules you must follow, if you are ever to return to the shelves you know:

1. Respect the books.

2. Follow the Dewey Decimal system.

3. If you meet a fellow traveller who offers you a banana, by all that you hold dear, say yes.