Walter, accompanied by his friend Tristram Griffen, a Saxon archer, sets out to make his fortune in Cathay (an alternative European historical name for China) during the time of the "Pax Mongolica". The pair join a caravan of gifts being sent by the merchant Anthemus to Kublai Khan, who is preparing to invade China. The caravan is under the protection of Mongol general Bayan of the Hundred Eyes. Impressed by Tristram's archery skill and his English longbow and Walter's scholarship, Bayan takes an interest in the Englishmen.