1/5/2018 ~~ I love this series, and I am sad to see the publication of the final book. It's one of the rare early chapter books that works for older readers too - readers who have difficulty finishing full-length chapter books, those who don't see themselves as readers, etc. It also works well for our youngest readers who are ready for more complex books without being ready for the issues and content they may have. Finally, there are enough inside jokes that adults will enjoy reading about Al's, Rip's, and Nikki's adventures.
Things cleared up: Why Mr. Hoarsely was the only adult able to see monsters. How/if Al's Leap Day birthday would be important. Why Dottie suddenly became unable to see monsters. I think readers will enjoy going back through all 12 previous books to identify the monsters wreaking havoc in town in this book (pp. 12-13, pp. 42-43: pranked, burnt, whittled, knotty, rusty, etc.)
Not cleared up: Why Al lives just with his dad; I've always wondered about the back story of his mom.