Boxcar children mysteries

Henry, Jessie, Violet, and Benny--four children who used to live alone in a boxcar and now reside with their grandfather--arrive at Camp Seagull overflowing with excitement, but they soon realize that some of the other campers are not above cheating in the annual camp Olympics.

The four Aldens take shelter in an old abandoned house during a rainstorm while on a bicycle trip to their Aunt Jane's house when a lost dog finds them.

The Aldens participate in a three-day bicycle ride and soon find that someone seems to be intent on keeping others from completing the event.

While staying at the Crooked House, the family home of their housekeeper Mrs. McGregor, the Aldens try to solve a riddle that will lead them to a hidden treasure.

The Aldens investigate when exotic and endangered animals begin to disappear from the zoo where their new friend Lindsey works.

The Aldens start a business producing birthday parties and find themselves investigating a series of robberies taking place during their parties.

A young Canadian visitor helps the Alden family solve a mystery involving a lost coin collection.

When they take their dog, Watch, for obedience training, the Alden children discover that some of the dogs in the class have vanished and decide to try to solve the mystery of their disappearance.

While visiting the Outer Banks of North Carolina, the Aldens see a mysterious wild horse that may be a ghost.

The Aldens try to help a visiting Russian gymnast who is surrounded by mysterious people and events and who seems to have a secret.