Andi is just about to turn 13 and she's ready to rebel, along with her two close friends, Buffy and Cyrus. However, Andi's journey is complicated by the arrival of her wild older sister, Bex. When she was a teenager, Bex was the poster child for rebellion. Now Bex stops by every year or two; where she and Andi usually enjoy an adventurous time together, and then Bex is off again. But this time, Bex is sticking around, and she's ready to get her life together. Unfortunately, that means tearing Andi's life apart.