Billie is 16 years old. She feels behind in almost everything. However, she's determined to catch up this summer. Working as a lifeguard at a water park with her two best friends, Rosine and Juliette, she meets a boy, a cycling champion, who catches her eye. Unfortunately for her, he's also the object of interest to her perfect sister, Annette, who has just broken up with her boyfriend. Billie will have to stand up for herself to avoid letting true love slip through her fingers. But is it really love that's finally appearing, or just a beautiful illusion?