Grandfather and Aunt Jane haven't spoken for years, but the children help them to once again talk to each other.

The Alden children travel on a Mississippi paddle-wheel steamer to visit an old family friend in his cabin near Hannibal, Missouri, and try to discover who is responsible for the mysterious activities near the house.

The Alden children have an adventure as they journey along with the Little North Railroad in two cabooses rented for the summer by their grandfather. A children's tale of adventure and excitement recounting the exploits of the Alden family's summer trip in cabooses

The Aldens investigate when exotic and endangered animals begin to disappear from the zoo where their new friend Lindsey works.

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

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