The Alden children 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 children solve the mystery.

The Alden children hunt for hidden treasure while helping their cousin Althea keep her beautiful home, Peacock Hall.

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 Aldens are on a special vacation up north to see the Calgary Stampede -- a cowboy celebration of Canada's frontier spirit! There's a parade through the streets of Calgary, a spectacular stage show, and plenty of fun things to do. But behind the scenes at the festival, an important piece of jewelry goes missing. Can the Boxcar Children find the thief before the big show is ruined?"--Jacket flap.

A family, snowbound in a vacation cabin, discovers adventure in surrounding wild life, three children they find in the snow, and a search for a lost recipe.

When their grandfather buys a bookstore at auction in New Orleans, the Alden children help clean it up and discover that several people seem to be obsessed with the store and its contents.

On a camping trip to Arizona with their grandfather, the Alden children search for a lost gold mine.

When the Aldens visit Yellowstone they discover a map showing the way to an old cabin where gold is supposedly hidden, but they encounter lots of interference in their attempts to hike the trail.

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

"The Aldens visit the shore in New Jersey and help out at an amusement pier that is rumored to be unsafe"--