Allie, now sixteen years old, is just one win away from becoming a full-fledged jockey. Everyone gathers at Tall Oaks to celebrate her achievement. At the festivities the jockeys and trainers reminisce about their favorite horses past and future. Inspired more than ever by their tales, Allie and her horse Wonder's Legacy set out for Whisper-wood to perfect their jumping skills and to look after a broodmare named Sterling Dream that is due to foal soon.

But a failed attempt at cross-country jumping forces Allie and Legacy to slow down. It's only when Sterling disappears that they get back on track. Will they be able to save the missing mare and her unborn foal in time? Be sure to celebrate the rich history of the Thoroughbred series with all your favorite characters in this spectacular concluding volume.