During the Middle Ages, Arabic, Turkish, Indus and Chinese cultures produced the worldÂ's best scientists, astronomers, mathematicians, physicians, poets and inventors at a time when Europe suffered through the Dark Ages. In 1057, a Viking slave ship kidnaps a youth off a beach in Wales and a boy from Normandy and sells them on an eastern slave market to a khan, emperor of 10 walled cities on the Silk Road. They are trained as horse fighters, then educated, one as a physician and the other an expert in agriculture and animal husbandry. They return to William the ConquerorÂ's Britannia and its immeasurable brutality. Though skilled fighters with the short sword and compound bow and capable of brutish behavior themselves, their intellect has been leavened by eastern knowledge, philosophy and religion. Declared heretics before the Norman court, they are released to trek across Britannia. They encounter assassins, Norman warriors, Saxon rebels and a bandit Welsh longbowman. History and the slavery of feudal England unfold as they fight their way to claim a fiefdom in the warring frontier of Wales.