Board Thread:Pitches/@comment-8475730-20150313014353/@comment-25375217-20150331212120

If I recall correctly (I haven't read it in awhile), the four kids are orphaned and told they have to live with their grandfather, but they're afraid of him. They run away and find an old boxcar to live in. The oldest starts working and finds a dog, they're living pretty happily, etc., but someone finds them and sends them to their grandfather, who they find out is a pretty cool guy. But they miss their boxcar and dog. The woman who owns the dog lets them keep him, and their grandfather brings the boxcar to put in his backyard as a clubhouse of sorts.

That all takes place in the first book, which would be either the pilot or the movie, obviously. The rest of the books take place at the grandfather's house with the boxcar and they go on adventures and solve mysteries and stuff.