Bad luck hits the Greenfield Museum with the addition of an ancient mummy exhibit. Annotation. The Aldens are helping the museum curator set up an exhibit about life in ancient Egypt. But the longer the Aldens are around the exhibit's mummy, the more things go wrong. Has the museum been struck by a curse from the ancient mummy? Illustrations.

Henry, Jessie, Violet, and Benny, working behind the scenes of the Greenfield Museum's special exhibit, attempt to solve the problem of missing Egyptian treasures.

The Aldens take part in a hunt at a gem mine and discover that someone is out to sabotage the contest.

While staying at the Crooked House, the family home of their housekeeper Mrs. McGregor, the Aldens try to solve a riddle that will lead them to a hidden treasure.

When an elderly friend is injured, the Alden children offer to help him with his window-washing business in their small town of Greenfield and agree to help him solve a riddle that has arrived in a mysterious invitation.

The Aldens help a farmer whose honeybees have stopped producing honey and discover a sabotage scheme.

When the Alden children join a group of volunteers to fix up an old house for senior citizens, they try to explain the puzzling behavior of their coworkers as well as investigate some unusual events.

The Aldens investigate to see if the ghost of an alligator is haunting the Louisiana bayou.

The Aldens are visiting Grandfather's friend Billie, who owns a fish camp in Alligator Swamp. One night Benny sees something in the swamp that no one can explain. Could it be the ghost of Gator Ann - a long-dead alligator - come back to haunt the swamp?