After a series of strange events, the Alden children must solve a mystery to help their friend Mike and his family.

"Henry, Jessie, Violet, and Benny used to live in a boxcar. Now they have adventures everywhere they go. At a lighthouse, the children find a mystery in the night!"

The Boxcar Children are spending the summer in an enormous New England farmhouse. Near the house there is an old woodshed that holds a surprising secret that dates from the Revolutionary War.

The Aldens' boxcar is the perfect place for games, picnics, sleepovers, and fun. But is it also the perfect place for ghosts? When strange things start happening there, Benny is convinced that the boxcar is haunted. Will the Aldens be able to scare away the spook...or is it good-bye, boxcar?

The Aldens agree to help Grandfather's friend fix up Skeleton Point, an old mansion. Skeleton Point is filled with old skeletons belonging to its former owner, and townspeople have seen the skeletons walking through the house.

The Alden family rents a houseboat to drift down the river, and encounters a mystery in the little towns along the river, involving a fast black car.

While exploring the caves around Dragon's Mouth Cavern, a series of unusual and somewhat frightening events convinces the Alden children that someone does not want them around.

The Alden children visit a family friend at his apple orchard which is rumored to be haunted, but instead of a ghost they find that some of the families' valuable antiques are being stolen.

The Alden children, isolated in a storm at a small bus station, are led into a mystery centering on a polluted river.

When the Alden children set out to solve a jewelry store robbery, they find they must also deal with a mysterious thief who steals their favorite cereal.