Double Dose — Peter Nelson

When her childhood friend is accused of being a drug courier, the seventeen-year-old amateur sleuth travels to the scene to prove her friend's innocence.
 
Mollie Fox has known Meredith Hughes since third grade. So when Meredith is busted for drug possession upon returning to San Francisco from a New York City fashion shoot, Mollie is certain her friend is being framed. Everyone else at Bayside High is convinced that Meredith is guilty simply because she's wealthy, beautiful, and privileged enough to think she might get away with it. But you're innocent until proven guilty, right? So when Meredith won't defend herself, Mollie jets off to New York to investigate.
 
Mollie goes undercover in the glamorous world of high-fashion modeling, and discovers a dangerous network of drug dealers that uses models as couriers. But just when Mollie thinks she's got this case figured out, she realizes that whoever set up Meredith won't be satisfied until she's dead. And he's threatening to take down anyone who gets in his way -- including Mollie.