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.
When Benny and Henry get summer jobs at a department store in town, they don't expect to be solving mysteries at work. But when an expensive vase disappears, the salespeople receive strange notes, and the jewelry display is tampered with, it's up to Benny to uncover the truth!
The Boxcar Children take a bus trip to the Science and Hobby Fair, but a bad storm forces them to stay at a bus station along the way. Soon they are in the middle of a mystery involving a polluted river, two strange boys, and a suspicious bus station manager.
When the Boxcar Children find a mysterious journal hidden behind the wall of the guest room, it leads them on a search for a valuable coin collection. But what happened to the journal's owner, and what is she trying to tell them?
At the beach, Benny finds a valuable gold locket and decides to try to find its owner. Soon the children are caught up in a puzzle involving strange visitors at the beach and the mysterious Miss Smith, who seems to live along in the big Tower House nearby.
At the beach, Benny finds a valuable gold locket and decides to try to find its owner. Soon the children are caught up in a puzzle involving strange visitors at the beach and the mysterious Miss Smith, who seems to live along in the big Tower House nearby.
A family moves into the house next door! The Boxcar Children decide to make friends with their new neighbors by building a tree house with them. In the process, they notice a window in their neighbor's house that nobody knows about. Does the old home have a secret?
A sudden snowstorm traps the Aldens in a mountain cabin! The cabin is cozy, but the children hear strange noises at night and find a coded message carved into the closet door. Can the children crack the code and solve their snowbound mystery?
Floating down a lazy river, Benny finds a blackmail scheme in progress.
A trip in a caboose at the end of a freight train leads to an old clown and a search.