Exposition (Initial Situation)
To Grandmother's House We Go
The premise of the book is that Joey and Mary Alice Dowdel (who live in Chicago) are being sent to rural Illinois to stay with their Grandma Dowdel for one week every single summer. At first, the kids aren't too stoked about this, but they come to enjoy spending time with the grandmother, who's totally eccentric—and lets them do all sorts of stuff their parents would never consent to.
Rising Action (Conflict, Complication)
Rough Roads Ahead
When the kids go to visit their Grandma Dowdel, though, they also witness firsthand the Great Depression and how it affects people in rural areas. This isn't always such a pretty sight, but their grandmother isn't going to sit around and do nothing about it. Almost every summer that the kids come to stay with her, she takes them on adventures to help those in need.
She shows them that you can do anything if you're fearless enough…even break the law.
Climax (Crisis, Turning Point)
Welcome Home, Mrs. Wilcox
The most upsetting thing that happens over the course of Joey and Mary Alice's visits to their grandmother is when Mrs. Wilcox—Grandma Dowdel's friend—can no longer make payments on her house and leaves to stay with her sister in another town.
Grandma Dowdel manages to convince the banker to give Mrs. Wilcox her house back, and she gets to return to town and live out the rest of her days with the people who care about her. Get it, Grandma.
The story slows down with the last summer that Joey and Mary Alice spend with their grandmother—the year of the Centennial Celebration. We see the kids enjoy their last visit before they're "too old" to keep coming and staying with Grandma Dowdel for a week every summer.
And they get to take part in the town's Centennial Celebration with all the friends that they've made here over the years, thanks to their grandmother.
Trains in the Night
The book ends with Joey joining the Air Force a few years later, when World War II breaks out. When he heads off to training, the train that he's on passes through his grandmother's town.
Even though it's the middle of the night and she can't even see him on the train, Grandma Dowdel is still outside her house and watching for him. She waves as he passes by, and he waves right back.