Petal, a young girl from Clonegal, Ireland, goes in the car with her father to the Kinsellas' house in the 1980s. The Kinsellas are relatives of Petal's mother Mary, and Petal goes to stay with them in exchange for work. Her mother is pregnant with another child, and the family cannot afford everything at the moment. When Petal arrives, Mrs. Edna Kinsella gives Petal a bath. Then she dresses Petal, who does not have clothes of her own, in baggy boy's clothes. The girl gets used to doing chores around the house and begins racing to the mailbox each day by Mr. John Kinsella's wishes to both get the mail and get faster. Petal feels ease at the Kinsella house. The couple takes her to get new clothes so that she can wear something nice to Mass. At the store, a woman tells Edna that Petal looks just like her, and Edna does not correct the woman's assumption that Petal is her daughter. When a townsperson dies one day, John and Edna take Petal to the wake because they feel they cannot leave her home. Another local named Mildred offers to take Petal back to her house so she does not have to stay in the place of grief. On their way, Mildred asks Petal questions about the Kinsellas and tells Petal that the clothes she was wearing belonged to the Kinsellas' son who passed away by drowning after following their family dog to a water tank. Petal tells John what Mildred said. He takes Petal out to a beach and lets her know that she never is obligated to tell anyone anything. They race. Not long after, Edna receives a letter from Mary telling her that the new baby has arrived. Petal will go home soon and be with her brother. Petal asks John to take her back but, before they are about to leave, Petal goes to fetch water and falls in the well. He takes her home a few days later, grateful that the girl only caught a cold. When Mr. and Mrs. Kinsella take off to go home without Petal, she runs out behind their car and catches up with them, faster than she has ever been. John picks the girl up and swings around, and Petal watches as her own father approaches them.