In the fall of senior year, Percy throws herself into weekends in Barry's Bay after buying a used car. She keeps swimming because Delilah warns her not to disappear into her relationship, but Percy is openly consumed by Sam. Their families learn they are sleeping together, Percy finds condoms from her mother in her bag, and she and Sam build a routine around his work at the Tavern, stolen make-out sessions, and quiet mornings discussing school, writing, and university plans.

As the year continues, Percy and Sam grow closer while an undercurrent of anxiety builds. Sam, Delilah, and Jordie all plan for Queen's, while Percy is expected to attend the University of Toronto, and Percy worries distance will end what they have. Their relationship feels increasingly accepted by both families during Thanksgiving and Christmas, and on New Year's Eve Sam tells Percy he is in love with her. Energized by that confession, Percy initiates a more intimate sexual encounter, and their bond deepens.

In the spring, Sam, Delilah, and Jordie are accepted to Queen's, and Sam also wins a major scholarship. Percy is admitted to U of T, but instead of feeling reassured, she feels left behind while everyone else seems to be launching into a new future. Sam tries to soothe her fears by making concrete long-distance plans and inviting her as his date to his graduation party, promising they still have the summer together.

At Sam's graduation, Percy is struck by how admired and accomplished he is. Watching him deliver the valedictory speech fills her with pride, but also with dread that he is becoming part of a larger world beyond Barry's Bay and beyond her. That fear becomes immediate at the bush party when Sam finally confesses he has been accepted into an intensive premed workshop and must leave in three weeks. Percy is hurt not only by the news, but by the fact that Sam kept both the application and the acceptance from her, and the shock ends with her vomiting on his shoes and riding home in tears.

The remaining weeks pass too quickly, and Percy's resentment mixes with grief. During their final lake crossing, Percy tells Sam that his secrecy makes the relationship feel one-sided; Sam insists she is his best friend and favorite person and promises university will not change them. After Sam leaves for Kingston with Sue, Percy struggles badly when more than a week passes without any real contact from him. Charlie becomes unexpectedly supportive, comforts her, criticizes Sam for being cowardly, and warns that Sam wrongly assumes Percy will always wait for him unless he fights for her.