If she could -- if her parents would let her -- eighth-grader Windy would change everything about herself. She'd get highlights in her hair, a new wardrobe; she'd wear makeup. But nothing ever changes. The mean girls at school are still mean, and Windy's best friend Elena is still more interested in making up words than talking about boys. And then one day, Windy gets the change she's been looking for. New girl Nina -- impossibly cool, confident, and not afraid of anyone -- starts hanging out with Windy! Nina even wants to be "breath sisters." Windy isn't sure what that means, exactly, but she knows she wants to find out. It sounds even better than a BFF. Windy is right, at first. Being a breath sister gains her a whole new set of friends, girls she feels closer to and cooler with than anyone else. But her inclusion in the new crowd comes at a dangerous price. Windy wants to change everything about her life ... but is she really willing to give up everything in the process?