Gertrude Chandler Warner

On a camping trip to Arizona with their grandfather, the Alden children search for a lost gold mine.

The Aldens head to Ladakh, a territory in northern India, to help save the elusive and critically endangered snow leopard.

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

When the Alden children join a group of volunteers to fix up an old house for senior citizens, they try to explain the puzzling behavior of their coworkers as well as investigate some unusual events.

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 Alden children are thrilled when a famous orchestra comes to their town to perform, and when an original Mozart score turns up missing, they solve the mystery of its disappearance.

When an elderly friend is injured, the Alden children offer to help him with his window-washing business in their small town of Greenfield and agree to help him solve a riddle that has arrived in a mysterious invitation.

While visiting Lake Lucille in the Adirondack Mountains, the Aldens hear stories about a monster in the lake and then encounter evidence that it may be real.

While sightseeing at the Alamo, the Boxcar children investigate the disappearance of a priceless ring from the Alamo museum.

When the Alden children and their grandfather visit Everglades National Park in Florida to solve the mystery of a missing ranger, they discover that a panther provides a clue.