Look, there's no way around it: Kristy and the gang are stuck in a time loop that sees them repeating the eighth grade over and over again until the final book is released. That sort of restrictive framing device doesn't leave much room for major life changes in the later books, but in Good-bye Stacey, Good-bye something huge happens: Stacey moves away from Stoneybrook. If that development didn't blow your kid mind, then I envy you, because I was devastated. Stacey's move is the real deal, and although she does eventually return, that doesn't change how emotional her farewell to her friends and charges is in the moment. In this book, Martin establishes that even though the girls won't age throughout the series, they will deal with the same realistic life changes that average kids face in the real world.