At the request of their distant relative Althea, the Boxcar Children arrive at her old Virginia mansion and investigate the mysterious incidents happening there.

The Aldens climb a mountain and find a mystery! The hike up Old Flat Top was only supposed to take a day, but a dangerous rockslide changes everything to reveal a hidden cave that just may hold a legendary treasure!

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 a 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.

The Alden children help out a storeowner at the Hope Harbor Mall and discover that someone is tampering with the merchandise shipments.

The Boxcar children uncover a mystery on a train trip from Boston to San Francisco.

Grandfather and Aunt Jane haven't spoken for years, but the children help them to once again talk to each other.

The children, who are spending the summer in a lighthouse on the New England coast, are disturbed by a mysterious woman walking the lighthouse grounds. Jessie's dog Watch wakes up growling almost every evening at midnight, and Henry finds a puzzling note in the sand.

A friendly writer with a metal detector, the mysterious inhabitants of a tower house, and the discovery of a locket in the sand are ingredients for the Aldens' latest mystery.

The Aldens investigate when the arrival of several suspicious characters in Greenfield coincides with a mystery involving a popular boy actor.

The Alden children save an old woman's house, land, and all the animals in her animal shelter from greedy contractors.