HTV's adaptation of Marguerite Henry's children's adventure story boasts the sort of cast usually reserved for Agatha Christie ( a couple of lines apiece for Harris and Jackson; others guilty of accepting insupportable roles). The leads, however, go to young Navin Chowdry (from Madame Sousatzka) as a mute Arab orphan, and the feisty colt he grooms for the Bey of Tunis. Presented as a gift to King Louis XV of France, the pair's fortunes swing from aristocratic patronage to plebeian servitude, and back again, and back again, taking in at least six owners and locations as diverse as the French court and Newgate jail. This viewer would have been happy to trade the surfeit of plot for a touch of subtlety. But horses for courses: children will probably respond to these equestrian escapades, Chowdry makes a natural hero, and Duffell's economic direction at least ensures that the going is firm.