The secret is out! Well, all of the third-graders' secrets are out. A tattletale is loose in the basement of Sleepy Hollow Elementary and suddenly rumors are spreading about everyone. Now the class is playing the blame game. Is Cassidy the blabbermouth? Is Jeff the Big Mouth? Or is someone — or something — else spying on the basement class? Nina is ready to do whatever it takes to catch the snitch. But would she be willing to tell on her best friends?