While visiting a Navaho Indian reservation in New Mexico, the Aldens try to save a forest under threat of development by proving it is the site of a lost, buried village, but someone is sabotaging their dig.

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.

The Aldens accompany their grandfather to his class reunion and investigate the possibility of a buried Civil War treasure, and of a ghost in the bell tower, at Goldwin University.

The Boxcar children investigate the disappearance of a student's research paper from an observatory, and the subsequent disappearance of another student.

The four Alden children, aged six to fourteen, volunteer at the new recycling center in town, and help uncover who is breaking in and making a mess each night.

"One day in the park, the Aldens' dog, Watch, comes across a mysterious box with a note inside. 'Congratulations!' the note says. 'You've found it!' The box is part of a game called Geocaching. Soon, Henry, Jessie, Violet, and Benny are searching all over town for hidden boxes and making friends with other kids in the geocaching club. But is one of the club members a thief?" -- p. [4] of cover.

The Aldens investigate the rumors of ghosts, disappearing props and a haunted seat in the Trap-Door Theater.

When the Alden children and their grandfather visit Everglades National Park in Florida to solve the mystery of a missing ranger, they discover that a panther provides a clue.

While helping run Jerry Taylor's general store, the Alden children investigate his mysterious employee Nancy.

The Alden children hunt for their late grandmother's necklace that has been missing for years.