Most people are probably familiar with the lesser levels of book-borrowing hell, the tiers reserved for borrowers who hang on to a friend's book for a few weeks too long, or who dog-ear pages in books owned by non-dogearers, or return a book with a fresh coffee ring on the cover. Those sorts of mundane offenses. Sadly, I consort with much more advanced sinners, those who should resign themselves to an eternity into the darkest depths. Those who highlight passages they surely know I didn't like, with probable malice. Those who pen bratty margin comments in response to my margin comments. Just a few days ago, I became acquainted with the blackest category yet: a borrower who Sharpied certain of my comments (in a Trotsky biography, of all books!) out entirely. Just scratched black bars right over them. Scoundrel. You will burn.