"The Aldens spend the summer on their aunt's ranch! The ranch is a beautiful place, but it's also the source of trouble between Aunt Jane and Grandfather. As the Boxcar Children explore the land, they make an amazing discovery. Will it help mend Aunt Jane and Grandfather's relationship?"--Publisher's description.

Henry, Jessie, Benny, and Violet Alden meet Mike Wood and a strange chain of events begins. Mike's house is mysteriously burned down, a man in a blue hat appears, and the Alden's uranium mine is in danger of being sabotaged. The four youngsters solve the mystery.

The boxcar children travel to Maine, take canoes into the wilderness and live in a house exactly like the one on Surprise Island, except the Maine house is brown, not yellow. They untangle the mystery of the two houses. Relates the exploits of the four Alden children as they locate a missing man. The Boxcar children are determined to solve the mystery that surrounds an old yellow house on their grandfather's property. Strange things have happened...

"The Aldens spend the summer on Grandfather's island! Joe, the island's friendly handyman, helps them with anything they need, but as the children continue to explore their summer home, they realize there is more to the island--and to their new friend--than meets the eye."--Publisher's description.

After the Boxcar Children move in with their grandfather, they spend the summer having adventures on a private island.

The Alden children are helping their new neighbors build a tree house when they discover an attic window that not even their neighbors knew about.

Benny's friend accompanies the Aldens to the South Seas for a vacation on a supposedly deserted island where they find an unusual mystery.

The children, who are spending the summer in a lighthouse on the New England coast, are disturbed by a mysterious woman walking the lighthouse grounds. Jessie's dog Watch wakes up growling almost every evening at midnight, and Henry finds a puzzling note in the sand.

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.