In the second guerrilla book marketing campaign to make headlines in the German book biz this week, 750 unassuming bloggers, website operators, reviewers test readers and more opened their mailboxes to find a suspicious package postmarked only with the image of a skull peering out of a laptop screen framed by two pistols. Each package contained a note and a book filled with empty pages. The book, published by Lübbe and aptly called Das Buch ohne Staben (The Book Without Letters) in German, was originally published in English as The Eye of the Moon (Anonymous) — the supernatural, horror fiction follow-up to The Book With No Name.