The Beatrice Letters is a book by Lemony Snicket. It is tangential to the children's book series A Series of Unfortunate Events, and was published shortly before the thirteenth and final installment. According to its cover, the book is "suspiciously linked to Book the Thirteenth", although the British edition merely states that it "contains a clue to Book the Thirteenth".The book consists of thirteen letters, six from Beatrice Baudelaire to Lemony Snicket, six from Lemony Snicket to Mrs.