On Green Day, Cam and her classmates discuss ways to protect the environment, but when money collected for the school's new skylights disappears, Cam uses her photographic memory to solve the mystery.

The Aldens are determined to help their cousin Althea keep her beautiful home, Peacock Hall. Maybe they can find the mysterious treasure rumored to be hidden there. However, when a face appears in Jessie and Violet's window and the gardener, Tate, seems to be hiding something, the Boxcar Children realize there may be lots of mysteries to solve at Peacock Hall!

The fluffy, fearless Chicken Squad detectives are determined to find out who the new addition is in their yard, so, equipped with the latest surveillance gear, the chicks venture into the wild to get answers.

When a statue is broken during her class' overnight trip to the museum, Nancy, Bess, and George try to get to the bottom of the mystery and find those responsible.

Horrible Harry must defend his reputation as a detective by cracking the secret code of Mrs. Funderburke's lunch prizes.

King's human, Kayla, has baked some treats for a friend's new puppy, Thor, but some go missing and it is up to King to find the culprit.

The Aldens are spending the summer traveling on a houseboat! Throughout their journey, the children have the feeling that they're being watched. Someone is watching them — and the thing that he wants is somewhere on their boat! He'll stop at nothing to get it and it's up to the Boxcar Children to figure out why!

The mysterious disappearance of a reclusive neighbor's cat involves the Boxcar children in some complicated detective work.

The Aldens have found a mystery under their very own roof! When the children found an old journal behind the closet wall in the guest room, they never dreamed it would lead them on a search for valuable coins. What happened to the girl who wrote the journal — and what is she trying to tell them?

When the Aldens spend the summer riding on a train, they get to live in a train car once again - this time, they're staying in Caboose No. 777. The number is hard to forget, and indeed, the children meet people at each stop who seem to know it well. It turns out Caboose No. 777 has an unusual past - one that comes with its very own mystery!