The Mystery Horse: The Boxcar Children are spending their vacation on a farm. They learn to do everything from milking cows and making homemade jam to raising a barn. Then one day they spot a beautiful horse locked up in a stable. Who is the mystery horse? And why is it hidden?

The Mystery at the Dog Show: The Boxcar Children are going to a dog show. They meet all kinds of dogs, from a spotted Dalmatian to a big, hairy sheepdog. But then strange things start happening at the dog show, and no one knows why. Can the children solve the mystery and save the day?

The Castle Mystery: Henry, Jessie, Violet, and Benny are going to visit a castle! Built long ago, the castle is now being turned into a museum. As the Boxcar Children help to restore it, they see mysterious lights and hear strange music. Faces appear in windows — and then disappear. Can the children solve the mystery hidden within the castle’s walls?