*This is the ONLY edition authorized by the author, with updated text and new cover art*The Ghost Twins hop on a school bus to visit Hanover, their old school. A new school has been built around the old bell tower-a new school that's in deep financial trouble. When the twins explore the mysterious room at the top of the spiral staircase, they discover a secret that might save Hanover. But how can they make someone else discover it? Especially after they get locked inside?