It's a mystery every month from A to Z Mysteries author Ron Roy! It's November, and the younger siblings of the A to Z Mysteries detectives have a new mystery to solve. ''The twins' new neighbors are up to something! It's Thanksgiving, and a mysterious couple has moved in next door. Bradley, Brian, Nate, and Lucy must work out the clues: The neighbors have built a tall wooden fence. They've bought some strange parts for making . . . something. They've even put up a suspicious tent in their backyard, with a big, scary dog to guard it. What could they possibly be hiding?