Every summer of her life, Matilda Jones has returned to Cousins Beach—the place where nothing ever really changes. It’s where she’s always been the loud one. The fun one. The girl no one quite takes seriously. But this summer is different. At fifteen, Tillie’s not a kid here anymore. For the first time, she’s being seen. And not always in the ways she expects. Between sun-soaked days and late-night swims, old friendships begin to blur into something more. Jeremiah is still easy, still bright—but now there’s something underneath it. Something that lingers. And Conrad Fisher—the boy she’s loved for as long as she can remember—feels further away than ever… and somehow closer, too. Meanwhile, beside her, Isabel ‘Belly’ Conklin is stepping into a version of herself she’s always dreamed of, caught up in a quiet, growing connection with Tillie’s older brother, Nate. But underneath it all, there’s something no one is saying. A tension in the adults’ voices. A heaviness in Conrad’s silence. A feeling that something important is being kept just out of reach. Because while the teens are falling in love, making mistakes, and holding onto the magic of Cousins as tightly as they can— the adults already know the truth: This is the last summer before everything changes. And the worst part? They don’t.