" The library was still giving trouble: a few books in some of the more obscure corners of the stacks retained some autonomy, dating back to an infamous early experiment with flying books, and lately they'd begun to breed. Shocked undergraduates had stumbled on books in the very act.
Which sounded interesting, but so far the resulting offspring had either been predictably derivative (in fiction) or stunningly boring (nonfiction); hybrid pairings between fiction and nonfiction were the most vital. The librarian thought the problem was just that the right books weren't breeding with each other and proposed a forced mating program. The library committee had an epic secret meeting about the ethics of literary eugenics which ended in a furious deadlock. "

― Lev Grossman , The Magician's Land (The Magicians, #3)