The mystery of the mummy's curse: The Greenfield Museum is holding a special exhibit all about ancient Egypt, and the main attraction is a 4,000-year-old mummy. Ever since the mummy arrived, nothing has gone right for the museum or its workers. Has the museum been cursed? The Alden children are about to find out. The mystery of the star ruby: The Aldens take part in a hunt at a gem mine and discover that someone is out to sabotage the contest. The...