In Lyon, the capital of the French resistance, a secret meeting is held under orders from . The objective is to unite all resistance factions. The future of France is on the line. But when the meeting is raided by the Gestapo under , the 'Butcher of Lyon', the plan disintegrates and the leaders are captured. The movement has been betrayed. There is a traitor in Lyon. British undercover agents and are sent to France. They must find the informer and save the resistance. But the Gestapo is on the hunt. More traitors emerging from the shadows. The net is closing.