A new family moves into the house across the street from Jade's family. They are odd, and Jade's family hypothesizes that they could be time-travelers. The new family includes a girl who's about Jade's age named Sally. One day, Jade and Sally encounter each other while they are separately exploring the woods near their houses. They sit by a stream and chat, and Jade reveals that she knows Sally and her family have come from the future. Sally initially tries to deny this, but eventually shares with Jade that her father is a "temporal anthropologist," her mother a climate historian, and their jobs necessitate traveling back in time in order to do research on various time periods. Sally says it's a very lonely lifestyle, as they never stay anywhere long.

Sally and Jade begin to spend lots of time together, hiking in the woods, and as the weeks pass, Jade compiles a list in a notebook of everything she's learned about the future Sally comes from. The end of the summer approaches, and Jade sleeps over at Sally's house. Sally tells Jade that her family may be leaving soon, despite how much she herself wants to stay. Later in the evening, Jade opens up about her transgender identity, which has been hinted at throughout the story. Sally tells Jade that in the future she comes from, people move between genders all the time. This makes Jade feel more hopeful about her own future in the world.

A couple of days before school starts, Sally's mom arrives at Jade's house, distraught. Sally is missing, she says, and their family was supposed to travel today. Jade runs out of the house, promising Sally's mother she will find her daughter, and heads to the waterfall that she and Sally visit often together. She finds Sally sitting before the waterfall, distraught — her family is planning to time-travel today, to a new time period. She pleads with Jade to come to the future with her family, but Jade says that these woods are her home, and without them, she wouldn't be herself. After a while, Jade convinces Sally to return home with her and to leave with her parents. The girls promise one another they will find each other, in a different time. After Sally's family leaves, Jade returns to her house and briefly sees two women in their twenties appear before her, arms around each other, waving and smiling. They disappear, and Jade beams to herself at the prospect of this future with Sally.