When their favorite author fails to arrive as scheduled to speak at the local library, the Alden children investigate how he could board a train and never be seen again.

The Aldens help out at a medieval fair and try to find a valuable sword which has been stolen from the fair.

The Alden children are helping out at a radio station, and they're going to be actors in a live mystery show. But when strange things keep happening, people in town say the station is haunted. Can the Boxcar Children catch the radio ghost before the station's listeners are scared away?

Someone or something is making a mysterious tapping sound at midnight in the home of a famous inventor known for her one-of-a-kind clocks. There is an invention convention taking place in the home and the Alden children are competitors at the convention. Does the mysterious tapping mean trouble for the convention? The children are determined to find out.