In this exciting installment of the Magic Tree House series, the magic tree house whisks Jack and Annie away to ancient Macedonia. Their mission is to meet a great and powerful stallion. There, they encounter a young prince, Alexander the Great, and his fearsome, wild horse, Bucephalus. The children must use their wits and courage to help the future king tame the legendary stallion, learning a valuable lesson about patience, trust, and the incredible bond that can form between humans and animals in this thrilling historical adventure.