One day in early summer, Momma awakes the her 4 children (Dicey, James, Sammy, and Maybeth) and tells them they are leaving to Bridgeport, Connecticut to visit their Aunt Cilla. Halfway on their journey, Momma stops at a mall, leaves, and never returns.
When Dicey realizes Momma isn't coming back, she sets out to walk with the other children to Bridgeport with only 7 dollars, a change of underwear, and a map. After several days of buying cheap food and looking for change, they stop and rest at a State Park where they meet Edie and Louis, a runaway couple.
While staying at the park, Sammy steals food and money, causing the police to start looking for them and forcing the children to relocate.
Once again, the children are out of money but luckily befriend two Yale students, Windy and Stewart, who take them in for the night. The next morning, Stewart drives them to Bridgeport and leaves them at Aunt Cilla's house.
When the children arrive, they find out that Aunt Cilla has died and their cousin Eunice is currently staying in the house by herself. Eunice takes them in but forces James, Sammy, and Maybeth to attend church camp while Dicey stays behind and helps around the house. She also earns money on the side by washing windows around town. Dicey and the children learn about their grandmother, Abigail, whom they've never met before.
While working in town, Dicey decides to talk to the police about Momma's disappearance. The police locate her and find out that she is comatose in a mental hospital in Boston.
Dicey feels her and the children are growing apart and are very unhappy staying in Bridgeport. When Eunice threatens to give Sammy up to the state for fighting, Dicey acts quickly, and takes the children the next morning to board a bus to their grandmother's home in Crisfield, Maryland.
When the children reach the bus station, they board it to Wilmington, but miss the bus going to Crisfield. Dicey panics and boards a bus to Annapolis where they meet Tom and Jerry. They sail them across the bay, where a circus is being held. The children befriend the proprietor, Will.
After a few days, the children see a sign advertising work picking tomatoes for a local farmer named Rudyard. The man does not seem trustworthy, but since the children needed money, they worked through the morning. When Dicey feels that Rudyard means the kids harm, they run away into the night and he chases them. The next day, he finds them again in a nearby town, but luckily, the circus was in town that day and Will protected them.
The children stay with the circus for the next few days and Will offers to drive them to Crisfield when the circus is in a nearby town. When they finally get there, Dicey decides that they need to face this challenge alone and arrive at their grandmother's home.
Their grandmother lets them stay for the night but refuses to let them stay for good. The children decide to work and postpone their departure, hoping she will get used to them. About 5 days later, Will pays a visit, and brings each of them a bicycle. That night, their grandmother explodes when Sammy rides off without permission and Dicey refuses to let her send him to bed without dinner. She asks one last time if they can stay and she says no.
Later that night, Abigail explains to Dicey that she has little money and no income and that is why she cannot take them in. She loves her new independence and freedom that she gained when her stern husband died 4 years back and she is afraid of running the children off, just as her mother did. As much as she wants them to stay, she states that she cannot let them stay and writes Eunice a letter about the children.
For the next few days, Abigail seems to not remember the conversation her and Dicey had. She takes the children to town to register them for school, because she's not sure when Eunice will write back about taking the children back or not. On their way back home, Dicey realizes that her grandmother hasn't mailed the letter and reminds her. Before Abigail can get to the letterbox, Dicey stops her and tells her that she should take them in, whether she wants to or not. To her relief, she agrees, and they all return to their new home.
A few more days pass by and the children finally reach the Connecticut River. They have run out of money and Dicey decides to wash windows and have the other children carry groceries at a local store to earn money. When they have enough money, they continue East and reach New Haven.