In 1277 England, the discovery of a Roman hoard sparks a deadly shadow war between English and French spies. On the streets of Paris, French agents seize an English agent, Lady Clemence d'Lisle, and she disappears. Thieves brazenly steal the king's gold en route to Westminster, and the King's Man, Simon Lowys, untangles a complex web of murder, Welsh rebels, deception, and elusive assassins. Simon questions his calling as a man of law when he sees justice obscured by duplicity and lies.