The Alden children discover clues that could help them figure out why a man vanished from a run-down yellow house on Surprise Island.

The children are spending the summer on their own private island but there is a mysterious stranger on the island.

A family starts out on a one-day mountain climbing excursion that becomes very exciting. In fact, it becomes an adventure for the former "boxcar" family. They unearth some mysteries and have a fine time in the process.

Violet and Jessie begin an adventure when they journey to Centerville to keep Aunt Jane company on the family ranch.

While canoeing and backpacking near Timberwolf Lake, the Aldens receive strange warnings to stay away from the area and stumble upon clues to a missing cache of stolen coins.

The Aldens search for carousel horses that have disappeared from an amusement park.

The Alden children discover another mystery when they agree to help injured Mr. Yee tend to his plot in the community garden and find out that vegetables are going missing and plots are being vandalized.

The Aldens are helping out at a doughnut shop, but when a rival store opens across town, strange events follow, and the children have a mouthwatering mystery to solve!

"The old abandoned school in Silver City is being fixed up as an art center and the Boxcar Children volunteer to help clean up the place. But the other volunteers are scared by the spooky goings-on in the school--doors lock by themselves, and chalkboard messages appear out of nowhere! Will the Aldens find out the secret of the haunted school?"--