User blog comment:PurplePenguin/The Grunkle Stan Mystery/@comment-24.98.222.98-20120907201705/@comment-67.54.173.224-20121021190125

Actually, in Tourist Trapped, Dipper explains that the pages suddenly stop in his third book, as though the author "mysteriously disppeared". I think the author filled books with his supsicouns, then went ot another book. But if they didn't fill up the third one, that means the third is the last one. Then again, there could also be five books, and the author left some pages blank for the holder's suspicouns. I think Stan is the author, and he's planning to train five kids, giving each a book, and the sixth fingure could stand for Stan.