Dink, Josh, and Ruth Rose are absolutely thrilled to cheer on Uncle Warren's incredibly speedy racehorse, Whirlaway, at the biggest and most important racing event of the year. But the loud excitement screeches to a sudden halt when the champion horse completely disappears from his stall right before the competition begins. Mysteriously, the horse shows up the very next day, just in time to run the race, but he suddenly runs terribly slow and loses the entire event. The three smart friends immediately know that something is very wrong with this strange, confusing situation. Head down to the dusty stables and help the young detectives investigate this wild animal mystery from the ground up. You will have to ask the right questions and carefully inspect the grassy racing grounds to figure out exactly what happened to the once-fast horse.