From the moment the battle-scarred horse Bucephalas, allows a prince and a runaway girl to sit on his back, he is bound to them for ever. The prince is the young Alexander, who he proudly carries into battle, blazing a trail to the very edge of the world in his master's search for glory and adventure. The girl, Charm, is a lowly stable girl, who brushes away the ghosts Bucephalas sees and forgives his arrogant ways. But unlike the golden Alexander, Charm has darker reasons to stay by his side. Through the eyes of the horse, history, mystery and adventure unfold.