How does Little Fires Everywhere end?
The novel's central mystery—who set the fire that destroys the Richardson house—is resolved as being Izzy, the youngest and most rebellious Richardson child. After Mia and Pearl are forced to move out (Elena discovers that Pearl's name was used at an abortion clinic for Lexie's abortion, and this, combined with her investigation into Mia's past, prompts her to evict them), Izzy is devastated to find the rental house empty when she goes looking for Mia, the one adult who ever really saw her. Feeling that her siblings have each used and betrayed Pearl, and consumed by rage and grief, Izzy pours gasoline on each of her siblings' beds and sets the house on fire, not realizing her mother Elena is still inside. Elena escapes unharmed.
Before leaving town, Mia has quietly left behind photographs for each Richardson child, images with personal significance chosen specifically for them, a final act of connection and understanding despite everything that happened. Mia and Pearl then leave Shaker Heights for good, with Mia planning to finally reconnect with her own estranged parents and to help Pearl find her biological father, the truth about her origins having already been revealed to Pearl (Mia had once been a surrogate for a wealthy couple, the Ryans, but could not go through with giving up her baby and fled with Pearl instead).
The custody battle over the little girl at the heart of the town's other central conflict resolves outside the courts: after losing her legal case, Bebe Chow, inspired by something Mia said to her, sneaks into the McCulloughs' home and takes back her biological daughter, May Ling (whom the McCulloughs had been raising as Mirabelle), fleeing with her to Guangzhou, China. The McCulloughs spend a fortune searching for them without success, and eventually move forward with approval to adopt a different baby from China instead.
In the aftermath, Izzy runs away from home, having taken the contact information for Mia's parents, determined to keep running rather than ever be forced back into her old life. The book closes with Elena Richardson, whose life had been built on order, rules, and control, confronting the realization that her worst fear—losing her daughter—has actually come to pass, and vowing to spend the rest of her life searching for Izzy.
✓ Fact-verified against independent sources