When a world-famous trick riding horse vanishes just days before the biggest event of the year, the police brush it off as a publicity stunt. But the desperate owner knows better—and hires the Robinson Family Detective Agency to bring the prized stallion home. With the trail running cold, Becky Robinson goes undercover as a stunt rider. The only problem? She can’t even stay on a pony, much less perform death-defying tricks.

Just when Becky thinks the trick riding case is in the bag, another heist sends shockwaves through the art world. The elusive Sunlight Swindler has stolen priceless masterpieces for years, but now he's escalated—to murder. When one of Becky’s own team members is framed for the crime, she must expose the real thief before the agency’s reputation is ruined.

With time running out and the stakes higher than ever, Becky must outwit the crooks before they ride off into the sunset—or disappear into the starry night.