Book excerpt: You know when Nils comes to you and Pippa for help, the situation must be dire, and it is. His little sister’s stuffed dinosaur has gone missing, and she is inconsolable. Pippa’s not keen to go to Nils’s house, but she never could resist a good mystery. As she always tells you, though, mysteries are about secrets and the more mysteries you solve for Nils, the more secrets you learn. Perhaps this time you can discover a secret that can heal the rift between you, or perhaps you’ll discover one that makes it worse than ever. See if you can solve the mystery before Pippa does!