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

While helping their grandfather prepare for Greenfield's Winter Festival, the Alden children uncover a mystery surrounding the statue in the town square.

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 attempts to befriend the new girl Beth frustrated by her strange behavior.

Bad luck strikes the Aldens when they help set up an exhibit at the Greenfield Museum. The main attraction is a 4,000-year-old mummy, and the longer the Aldens are around the mummy, the more things go wrong. The children soon wonder if it has brought with it an ancient curse.

Six children help solve the mystery of a missing spyglass that has kept two brothers feuding for years.

When their grandfather arranges for them to spend two week at Sunny Oaks, the four Alden children enjoy settling into the routines of farm life but become suspicious about a mysterious horse locked in the stables.

The Aldens try to help a visiting Russian gymnast who is surrounded by mysterious people and events and who seems to have a secret.

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 away other campers.

The Aldens search for carousel horses that have disappeared from an amusement park.