Summer vacation on an almost private island gives the Aldens a challenge. Henry, Jessie, Violet and Benny used to live alone in a boxcar. Now they have a home with their grandfather and are spending the summer on their own private island. There is a mysterious stranger on the island with a secret--but that's not the only surprise in store for the Boxcar Children.

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 Aldens are visiting friends for a big Dia de los Muertos celebration. The kids love learning about the holiday and helping out--that is until mysterious events threaten to ruin everyone's preparations. Can the Aldens figure out what's going on and help their friends save the celebration?

When a professional hockey player comes to Greenfield with plans to build an ice skating rink, the Alden children suspect that someone in town wants to stop the project.

When the Alden siblings visit their grandfather's friend in an apartment building, they begin to wonder about the many mysterious events that keep happening on the thirteenth floor of that building.

The Aldens travel to Ireland to explore castles. While visiting Duncarraig Castle the children discover a cloaked figure roaming around. Could it be a banshee?

When the Aldens agree to watch the house of a local author who has written a book about a vampire, they end up investigating activities that are suspiciously similar to those in his book.

The Alden children, isolated in a storm at a small bus station, are led into a mystery centering on a polluted river.

Someone is trying to put Aunt Jane's motel out of business, but the Alden children aren't going to let that happen.

While visiting a Navaho Indian reservation in New Mexico, the Aldens try to save a forest under threat of development by proving it is the site of a lost, buried village, but someone is sabotaging their dig.