Summer vacation on an almost private island gives the Aldens a challenge. Henry, Jessie, Violet and Benny used to live alone in a boxcar. Now, they have home with their grandfather and are spending the summer on their own private island. There is a mysterious stranger on the island with a secret --but that's not the only surprise in store for the Boxcar children

Henry, Jessie, Violet and Benny share a mysterious island for the summer with their grandfather.

The Alden children discover another mystery when the 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.

Contains three mystery novels featuring the Boxcar children; including "The Mystery at the Ballpark," "The Mystery of the Hidden Beach," and "The Summer Camp Mystery."

Relates the exploits of the four Alden children as they locate a missing man