Jeannette Walls, successful socialite and journalist, is on her way to a fancy-schmancy New York City party. Looking out the window of a taxi, she watches a homeless woman. It's her mother. Jeannette realizes she needs to check her privilege, and she tells us the story of how she got to where she is, schmoozing with society folk while her Mom is literally in the gutter.
Jeannette's childhood memoir begins when she is three years old. She is cooking her own hot dogs on the stove. Oh, she wishes she were an Oscar Mayer wie-NAAAAAARGH! Jeannette sets herself on fire and must be rushed to the hospital, where she receives skin grafts. To avoid paying the hospital, Dad takes her from the recovery ward in the middle of the night, and the family skedaddles to another town.
Over the next few years, the Walls family—Mom, Dad, Lori, Jeannette, Brian, and Maureen—bumps around the southwestern United States, from Arizona to California. Jeannette falls out of a car. Brian almost falls out the back of a U-Haul. Maureen wakes up with a rat in her bed. The Wallses move around a lot because Dad can't keep a job and because Mom fancies herself a modern-day Picasso, even though she can't sell a painting.
When the Wallses are up against the figurative wall with no finances and nowhere else to go, they decide to move in with Dad's mom, Erma, in Welch, West Virginia. Erma should be living out West, because she is truly a wicked witch. She keeps the kids in the basement, forbids them to laugh, and molests Jeannette's brother, Brian. And Mom and Dad let it happen. They don't want to go against Erma and risk getting kicked out.
Eventually, Dad saves up some money to get a house for the family to call its own. By "house," he means a barely standing shack with no indoor plumbing. This is what real estate agents call "rustic" or "quaint." Dad is a man of big dreams, and he promises to build the family a new house, called The Glass Castle. Jeannette and Brian, wanting to help, dig a foundation to build their new house on. The foundation hole soon is filled with garbage.
The family is on the brink of starving. Mom finally gets a job, but Dad drinks away the paycheck. Jeannette makes a budget and tries to protect the money, but Dad always spends it. He even takes Jeannette to a bar and lets a man force himself on her. She pushes him away, and her faith in her father has finally broken.
Realizing that her whole life is filled with garbage, Lori wants to move to New York City. Jeannette, while working at her high-school newspaper, also gets a job to save up some cash to move her sister to the Big Apple. Dad steals the money, wanting to keep his kids at home, but Jeannette and Lori succeed in scrounging up bus fare, and Lori ships herself off to the West Village.
Jeannette soon joins Lori, along with Brian and Maureen. They're leading a happy big city lifestyle, but it doesn't last long. Before they know it, even Mom and Dad have hauled their sorry butts to New York. The freeloading parents take advantage of their kids, staying with them and not contributing to rent, until the kids decide to kick out their parents. Mom and Dad are now homeless.
After Maureen loses it and stabs Mom, she is put in a mental hospital and later travels to California. Lori becomes a successful artist, Brian a cop, and Jeannette a successful journalist. Meanwhile, Mom and Dad squat in an abandoned apartment building. Dad gets sick and says goodbye to Jeannette, who makes peace with the fact that her parents were awful but that her upbringing made her into the successful, determined woman she is.
The book ends with the family having a mini-reunion at the home of Jeannette and her second husband. Lori, Brian, and Mom are there for Thanksgiving dinner. Before they stuff themselves with turkey, they toast Dad and tell wild Walls stories. The end.