A bike trip in the country leads to a dangerous twist as Nancy's ride takes a sudden, nasty turn. After catching a jewel thief in the act, Nancy hopes to steal a little time for herself. A three-day bike ride with Ned, George, and a group of Emerson College students seems the perfect escape—until a series of "accidents" puts them all on a definite downhill course. And to add insult to injury, the rider most at risk is Nancy's friend George! But why would someone want to harm George—a girl who has never hurt anyone? Nancy knows she'll have to find answers quickly before the trip takes a dangerous detour and her friend's ten-speed spins out of control. A deadly secret has come along for the ride, and getting it out in the open may be the only way to save George's life!