Henry, Jessie, Violet, and Benny used to live alone in a boxcar. Now they have a home with their grandfather, and they're fixing up their boxcar so they can ride it in the big Greenfield Founder's Day parade. There's just one problem: Someone has stolen the boxcar... with their dog Watch in it! If only they can find the missing boxcar, it will lead them to Watch.
Can the Boxcar Children solve their most important mystery ever?