The ocean gives and the ocean takes. Quinn Kessler has known this since her first summer at her aunt's beach house in Piper Island. For eight transformative summers, the ocean gave her sun-kissed adventures with best friends, bike rides, katydid songs, fireworks. The ocean took away the pain of her father abandoning her. The ocean gave her a sticky, sweet first love, constellations, Ferris wheels, moon jellies. The ocean took away her fear. But one day last summer, Quinn learned that her hard-earned happiness was just the prequel to everything that would come after.When she returns to Piper Island for her final summer before college, everything once golden has faded to gray. Dead flowers, broken pinky promises, and snarling waves. The clock is ticking for Quinn to figure out her unresolved feelings for Everett Bishop, the boy who's always been her moonlight, as she struggles to accept happiness in a universe that could take it all away again in an instant. Grappling with sunny and salty memories from summers past, Quinn is ready to start living again, if only the universe could give like the ocean does.