This is the final novel of the My Friend Flicka trilogy. In this story, Thunderhead, Ken's wild white stallion, has escaped his remote mountain valley and is stealing mares from the Wyoming ranchers. In his band of stolen mares is Crown Jewel, a valuable racing filly. Ken's search for Thunderhead and Crown Jewel takes him through three states. And, for the first time in his life, Ken finds a challenge to his loyalty and fierce affection for his horses. Crown Jewel belongs to young Carey Marsh. With the fates of their horses bound together, it is natural that she and Ken should see a great deal of each other. Before he realizes it, Ken McLaughlin loses his heart to Crown Jewel's captivating mistress.