The Aldens investigate when an old wooden mask they have found is stolen.

Jessie wants her science fair project to make a difference. So when she gets the chance to test a local creek for pollution, she can't wait to get started. But when things start going wrong with her experiment, Jessie and her siblings don't just have an experiment to investigate, they have a mystery to solve!

"The Aldens are volunteering at the local recycling center, where they find plenty of things that can be reused, including a piñata that Benny takes home. But when the center is vandalized,the Boxcar children have a mystery to solve. is there treasure amidst the junk?"--P. [4] of cover.

The Aldens discover there's nothing more fun than a drive-in movie. But pranks and other odd things are happening at the Diamond Drive-In, and late at night, a ghost is seen walking around the empty lot. Is the old theater really haunted?

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 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 try to solve a series of mysteries which took place in a old hotel in Kansas which they visit.

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 Alden children suspect that the other guests are somehow involved when things begin to disappear at the bed and breakfast where they are staying in Washington, D.C.

"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?"--