Rosie Sinclair is just a typical teenage girl -- except that her best friend is an exotic dancer and her beloved grandad is involved in just a bit of crime. When he has the bad luck to get busted on the last job of his career, he turns his cell phone and the keys to his black Mercedes over to Rosie for safekeeping while he's inside.

Although Rosie has to cart around her grandad's elderly friends -- the wrinklies -- on their errands, she soon realizes that the Mercedes has its benefits: It helps her land dates with two of the hottest guys in town. Life is looking pretty rosy until the day she gets the first threatening call on her cell phone. A jewelry heist has gone wrong, and every crook in town thinks her grandad has something to do with a diamond ring that's missing. With his safety in jeopardy, Rosie sets out to solve the mystery. But can she find the answers before the icy voice on the other end of the phone finds her?