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.

Henry, Jessie, Violet, and Benny begin to dig into the past of the old boxcar turned playhouse in their back yard and discover clues about why it is being haunted.

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

The Aldens investigate when an artist who is participating in an art gallery contest is accused of being an imposter.

Henry, Jessie, Violet, and Benny, visiting their friend Fran in Wisconsin, become suspicious when it appears that Fran's family ghost, which has not been seen in years, is staging a comeback.

The Boxcar Children rush to get the scoop when it becomes apparent that someone is trying to shut down the Ice Cream Barn.

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.

While visiting their cousin's pineapple plantation in Hawaii, the Aldens hear a local legend about a black pearl with a curse on it and investigate mysterious incidents on and around the plantation.

The Alden children plan to ride in their boxcar at the Greenfield Founders' Day Parade, but the newly refurbished boxcar is stolen a couple of days before the big event.