The fourteenth century is probably best remembered for the conflicts that raged between England and France, known collectively as the Hundred Years War. Begun by Edward III of England who laid claim to the throne of France, it had eventually run its weary course by the reign of his weak and ineffectual grandson Henry VI. Yet in 1370 the Hundred Years War was only a half of the way through, with England in imminent danger of losing most of her territorial possessions in France. At this critical moment in time, Geoffrey Chaucer, court envoy, ambitious poet, and protege of the king's powerful son John of Gaunt, is sent on a secret mission to the territory of the Comte de Guyac to persuade the French nobleman to stay loyal to the English cause. After a hazardous journey, Chaucer and his companions reach Guyac's stronghold on the Dordogne in south-west France. The welcome is warm - Chaucer was once in love with Isabelle, the Comte's sister - but within a few days everything has changed. At the end of a hunting expedition, Guyac's body is discovered with a crossbow bolt through the throat. Suspicion points at the new English arrivals. So Chaucer must discover the real culprit if he is to save his own neck. The investigation will turn the poet and diplomat into a fugitive and the truth will not emerge until Chaucer joins Gaunt's brother Edward - known to history as the Black Prince - at the siege of Limoges, one of the crucial events in this endless war.