The Alden children have another mystery to solve when they visit a castle and must figure out which of the guests has stolen the Stradivarius vio

When their favorite pizza restaurant almost goes out of business, the Alden children try to help their friends stay open while they find out who

At an old library, the Alden children discover a boy who needs their help and a stranger who is after a valuable object they found in the library

At an old library, the Alden children discover a boy who needs their help and a stranger who is after a valuable object they found in the library

One warm night four children stood in front of a bakery. No one knew them. No one knew where they had come from. Henry, Jessie, Violet, and Benny

When the Alden children spend a week visiting at Pilgrim Village, they uncover the mystery behind the unusual happenings at the historic site.

The Aldens become involved in a community theater production of "The Wizard of Oz," which is systematically and mysteriously being sabotaged.

At the same time that the Alden children's efforts to raise money for a new hospital wing are being sabotaged by nasty tricks, they find their at

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

The Alden children uncover a plot to sabotage the Greenfield Bears baseball team. Includes baseball puzzles and activities.