When Billy Martin scores eight tickets to the prestigious Olympic Equestrian Team Trials held in Las Vegas, the Doubletree kids are delighted. The first day of showing brings thrills as a hometown girl they all know places third. Late that night, Becky Edwards gets a call from her old trainer asking for help in an emergency. While at the barn braiding horses for the next day's classes, she hears two men talking about drugging a horse. She recognizes one voice although she can't place it at first. At the show the following day, Sirocco, a highly rated champion mare, is eliminated from the competition due to steroid abuse, and a horrific accident takes one of the top scoring riders out of contention on a permanent basis. Determined to get to the bottom of both mysteries, the kids go sleuthing and what they turn up exposes a part of the show world they never knew existed. Join them in mystery, intrigue and high adventure in this, the latest book in the Doubletree Kids series.