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

When Henry's magic teacher, The Amazing Arthur, goes missing right before the Greenfield Magic Shop's annual magic show, Henry and his sibilings look into Arthur's disappearance.

The woodshed mystery: The Alden children are staying at the New England farmhouse where their grandfather grew up and find a surprising secret. The lighthouse mystery: When the Alden's take a summer trip to the New England coast, they have a fun place to stay: a lighthouse! Mountain top mystery: The Alden's climb a mountain and find a mystery.

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

The Boxcar Children investigate a mysterious ghost with a glowing pumpkin head at a friend's farm.

The Alden children stumble upon a mystery when they enter their dog, Watch, in a contest that could lead to fame and fortune, but where things keep going wrong.

The Alden children discover another mystery when they agree to help injured Mr. Yee tend to his plot in the community garden and find out that vegetables are going missing and plots are being vandalized.

At an old library, the Alden children discover a boy who needs their help and a stranger who is after a valuable object they found in the library.

The Alden children uncover a plot to sabotage the Greenfield Bears baseball team. Includes baseball puzzles and activities.

The Alden children travel on a Mississippi paddle-wheel steamer to visit an old family friend in his cabin near Hannibal, Missouri, and try to discover who is responsible for the mysterious activities near the house.