Zhao Xuan, an orphan from the Southern Song Dynasty, was originally a low-level craftsman in the Yuanting Firearms Camp. After witnessing spies from the Western Holy Grail Organization stealing the core technology of "Sky Fire", he was involved in a secret war of civilizations across Europe and Asia. Kublai Khan was furious and ordered the sealing of all firearm secrets. Zhao Xuan was ordered to do so at the critical moment, transforming from a skilled craftsman into a secret-keeper. He not only has to deal with the dignitaries of the Yuan Dynasty, but also hunts down the Holy Grail assassins lurking on the Silk Road, and he also has to struggle to choose between faith and loyalty. When sparks flow westward and wolves pass by, can he, as a mortal, block the leakage of the fire of civilization? A hidden epic lost in the annals of history begins.
