While on a camping trip with their grandfather, the Alden children try to find out about the loud music and missing food that threatens to scare

When the Alden children set out to solve a jewelry store robbery, they find they must also deal with a mysterious thief who steals their favorite

The Alden children investigate various mix-ups at a zoo run by their grandfather's friend in an effort to save it not only from pranksters but al

The Alden children investigate various mix-ups at a zoo run by their grandfather's friend in an effort to save it not only from pranksters but al

While visiting Chicago with their grandfather, the Alden children begin receiving mysterious clues to a treasure hunt. Includes related puzzles,

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

While on a camping trip with their grandfather, the Alden children try to find out about the loud music and missing food that threatens to scare