The year is 1490. Two unemployed wandering minstrels, Englishmen Bavol and sidekick Godwin, are on a temporary gig as customs officials on The Silk Road mountain border pass between China and Kashmir.
Italian Cardinal Vincent returns from a trade mission for the Duke of Milan (Leonardo da Vinci's boss) and wants to cross with his load of weapons and kitchen equipment, but he doesn’t have any paperwork. Bavol insists on doing things by the book. Neither man gives way.