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 also from the town council.

When their grandfather arranges for them to spend two weeks 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 Alden children suspect that the other guests are somehow involved when things begin to disappear at the bed and breakfast where they are staying in Washington, D.C.

The mysterious disappearance of a reclusive neighbor's cat involves the Boxcar children in some complicated detective work.

The Alden children investigate when Mrs. Murray's jewels are stolen during a party for the Starlight Skating Troupe.

Benny wants adventure and finds it as he and the other Alden children help uncover the plan of those who would prevent ballooning from coming to Lloyd's Landing.

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

While visiting a friend of their grandfather's on Sullivan's Island, off the coast of South Carolina near Charleston, the Boxcar Children encounter mysterious activities related to rumors of a buried pirate treasure.

While exploring the caves around Dragon's Mouth Cavern, a series of unusual and somewhat frightening events convinces the Alden children that someone does not want them around.

While helping out part time in a pet shop, the Alden children discover an employee who is smuggling and selling exotic animals.