Nancy's friend George is competing in a 3-day mountain bike race in Costa Rica, and her cousin Bess and Nancy are her support team. But Nancy might have more than one rider to help out when she discovers that someone is taking dangerous steps to make sure top U.S. cyclist Derek Woodhall doesn't win. Could last year's winner be the culprit? He didn't like it when Derek took an early lead. Or maybe Derek's publicist? She seems a little too happy about the press her client's misfortune is generating. There's not much time to figure it out, but Nancy is up for the challenge--whoever the culprit is, he or she certainly picked the wrong race to sabotage! Recommended for ages 8 to 12.