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

When the Aldens help a friend of their grandfather's to build the world's largest yo-yo, they soon discover that more than one person is trying to prevent them from finishing the job--and for more than one reason.

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.

When the Alden children accompany their grandfather on a trip to Seattle, they discover clues throughout the city, seemingly planted just for them.

Henry, Jessie, Violet, and Benny have never been to a drive-in movie theater before, but they_re visiting a friend who owns one. The children love to eat popcorn in the car and watch movies under the stars. But strange pranks are disrupting the fun_one night the sound system starts playing loud music during the movie, and a couple of the theater employees seem to be hiding a secret. Then, late at night, a ghost is seen walking around the empty grounds...

When the Boxcar children help out in a local garden, they dig up one strange thing after another! First, the tomato plants seem to move every day. Find out how that can be.

When the children uncover a strange puzzle in a friend's back yard, it's the start of a "spy game" leading to gold. But first they must make sense of an old photo and a riddle, and learn just who is behind this mystery within a mystery.

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.

People line up around the block to buy Mama Tova's cupcakes. But who could be trying to steal her secret recipe? The Boxcar Children follow clues to a cupcake contest, where they must use their mystery-solving skills to find a thief.