Some important papers and a student go missing from the observatory while the Aldens visit a college with their grandfather, they have to investigate both disappearances and see if they are connected.
The Boxcar children learn how hot air balloons work and even help launch one, but before they get the chance to ride in one they have to figure out who is trying to ruin the rally.
The Boxcar children are helping out at a guide dog training school, there they notice a rare obsession with a particular dog, Ginger, and other mysterious events.
Henry, Jessie, Violet, and Benny once lived on their own in a boxcar . . .It's spring, and all the baby animals are being born—a perfect time to visit the zoo. The Aldens and their friends are taking pictures there for a photo contest. But when cameras go missing and a girl is accused of cheating, the Boxcar Children must find out just who is monkeying with the contest!
Someone steals the newly refurbished boxcar the Aldens are going to ride at the Greenfield Founder's Day Parade, they only have a couple of days to find it before the event.
While visiting their aunt and uncle in San Francisco the Alden children visit Fisherman's Wharf. After they ride on their uncle's boat they discover something fishy is going on in the wharf and someone doesn't want Uncle Andy to catch any fish.
The Aldens are asked to be extras in a movie while visiting the Alamo but things are not picture perfect. They have to discover who stole a precious ring from the beautiful star, Claire, and they find out many people are jealous of her.