Billy Martin scores eight tickets to the Olympic Team Equestrian Trials in Las Vegas and the Doubletree show team is ecstatic as they prepare to attend the prestigious competition.
World famous riders and their horses converge on the Thomas and Mack Center to vie for the championship title. As the Trials get under way, the teens are surprised to see Yoli Navarro, a familiar competitor from home, enter the ring. She rides well enough to finish third on opening day and the kids cheer her on, hoping she can continue her winning streak.
Late that night, an old friend calls in a favor, and Becky Edwards goes to the show barn to braid some horses for the next day's classes. While working, she overhears two men talking about drugging a horse. One voice is familiar, but at first she can't place it.
After the men leave, she checks out the horse, surprised to see it's Sirocco, a well-known and highly ranked Grand Prix competitor. The huge mare seems unaffected by whatever the men gave her, so Becky shrugs it off.
The next day, Sirocco is eliminated from the competition for steroid violations. Even worse, Yoli is killed in a freak jumping disaster. Unhappy with the police verdict of accidental death and suspicious about the quality of her riding performance, Billy buys the show tape of Yoli's round and the kids go back to their hotel to check it out. Horrified, they watch in slow motion as the tragedy repeats itself on their TV screen. They decide her death was no accident, and determined to find out what really happened the kids go sleuthing.
They discover a side of showing they never knew existed and set a trap for some underworld mobsters. In the process, they also reel in a cold-blooded killer they once called friend.