The Alden children help out a storeowner at the Hope Harbor Mall and discover that someone is tampering with the merchandise shipments.

The Aldens help out at a medieval fair and try to find a valuable sword which has been stolen from the fair.

The Boxcar children have dinner at a Chinese restaurant and get a handwritten riddle in a fortune cookie! One riddle leads to another, and the children wonder who is leaving them the cookie clues, and why?

While visiting an old mansion, the Aldens investigate the possibility that it may be haunted.

Four orphaned children make a home for themselves in an abandoned boxcar and are united with their grandfather.

The Alden children draw upon their resourcefulness to save the neighborhood firehouse from being torn down, while they also face a series of mysterious incidents connected with it.

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.

When the Aldens help a friend of their grandfather's to build the world's largest yo-yo, they soon discover that more than one person is trying to prevent them from finishing the job--and for more than one reason.

The Aldens investigate when a new store called the Game Spot opens in town and the neighboring shops are robbed.