The Boxcar Children are in a show. Jessie is chosen to play the Cowardly Lion. Benny will play a munchkin. Even Watch has a part. Then mysterious things begin to happen.
Someone makes a threatening phone call and a costume is destroyed.
The Mountaintop Mystery 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 climbing mountains in New England. While investigating the disappearance of Spotzie, Mr. Woods's beloved cat, the Alden children discover that they are being followed by a strange man, receive threatening phone calls, and uncover a number of mysterious suspects in the catnapping. The Lighthouse Mystery Jessie sees a mysterious woman walking on the grounds of the lighthouse late at night. And Henry finds a puzzling note in the sand.