Thirteen-year-old Kallisto is a superb equestrian living in central Asia. Her mother breeds and trains Ferghana horses, and Kallisto often rides them to determnie which horses excel and should be bred. But when returns to her city after delivering a herd of horses to the nomad breeders, she discovers that the Chinese army is preparing to seize her city—and steal the famous Ferghana horses. It's up to Kalli and her friend to warn their families and protect the horses from the invading armies.