The narrator introduces herself as Mary Iris Malone, and she says that she’s “not okay.” 

Mim writes to Isabel. It’s presumed that the letter is intended for Mim’s Aunt Isabel, but by the end of the novel it’s revealed that the letters are for Mim’s in-utero half-sister. She explains how she resents her dad for moving her to Jackson, Mississippi, away from her mom and her hometown of Ashland, Ohio. She tells Iz that the letters she’s going to write will be her “Book of Reasons” that will hopefully explain the reasoning behind her actions.

Mim overhears her stepmother, Kathy, and her dad telling the school principal that her mom, Eve, is sick. Thinking that her mom needs her, she steals Kathy’s can of money, runs away, and buys a Greyhound ticket to Cleveland, Ohio. At the Greyhound station, she meets Carl, the bus driver, and Poncho Man, an older man who tries to flirt with Mim although she’s clearly underage.

Mim writes to Isabel to tell her why Labor Day is so important: It’s always been a special day between her and her mom. A group of “revolutionaries and idealists” in their old neighborhood used to throw a huge party on Labor Day (15), and Mim and her mother would go every year to revel in the rebellion of rejecting “suburban mediocrity.