Summer is adjusting to her senior year at Harbor School, with the year starting with her best friend Marissa Cooper expelled from Harbor as a result of her involvement in the shooting of Trey Atwood. As a result, Summer reluctantly seeks a more involved role in student politics, gaining a new rival in fellow student Taylor Townsend (Autumn Reeser). They have since become (albeit at times reluctantly on Summer's part) friends, particularly when Taylor helped her get Marissa back in by organizing a petition.