Buddy's a lucky dog. He gets to go to the fourth grade sleepover at school with Connor! He's hoping to find out more about the old legend of Agatha, the school ghost.   But the sleepover has plenty of other strange things going on, too: mysterious packages, secret notes, and whispers from a ghostly voice! Who—or what—is haunting Four Lakes Elementary?   The sixth book in the award-winning series The Buddy Files by Dori Butler delivers chills and thrills.