Once there was a bear who liked to wear underwear. One day he gets a mysterious message in the mail: there are ten hidden pairs of underwear and if he finds them he will end up somewhere special. There are some clues to show him where to go, but he's going to need some help! Fans of the titular Bear in Underwear (or bears or underwear) will find more to like in this book. It has the bright colours, the fun expressions, and the underclothing of the other books, plus the added fun of counting. There's not really a mystery per se, and the book isn't interactive (at least that I could see) in letting readers discover the underwear. But I could see crafty teachers and librarians being able to adapt this into storytimes (maybe as a felt story). The board book style will be a good fit with young readers, so check it out for adding it to a board book or concept book collection.