Autumn 1943. Three British agents working behind enemy lines are rounded up and shot. Who will be chosen to take their place?

New agents Emily and Vivien are parachuted into France but get a bumpy reception in more ways than one. Emily gets a reminder of her old life, and danger soon threatens in the unlikely shape of a pretty young woman.

The agents of the Outfit - at home and in Nazi-occupied France - have to cope with a series of crises. While Colin faces a breakdown and Vivien digs painfully into her past, Liz contemplates the wreckage of her private life and Emily must resolve an appalling personal dilemma.

Tensions in the circuit mount as Liz asserts her authority as the new leader. Gordon resents being bossed around by a woman. Vivien's mysterious behaviour arouses suspicion. And when disaster strikes, the team are forced to ask themselves: is there are traitor in their midst?

In the aftermath of the disastrous raid on the radio station the agents of Area 7 are faced with danger on all sides. How can they get treatment for the badly injured Gordon? Is there a traitor within their ranks? And what will happen when Emily disobeys orders for the first time.

With Emily on the run, Gordon invalided out, and Vivien increasingly obssessed with her secret search for her daughter, Liz struggles to prevent the disintegration of the circuit. She gets help from an unexpected source, but cannot stop the German noose from tightening around the beleaguered agents.

With Vivien and her daughter in German hands, Liz and the other agents of Area 7 are in grave danger, and they soon have to face a terrible dilemma. Which is more important? Their freedom or Vivien's life?

Emily is saved from arrest at a road block by local woman Nicole and the two women travel to Le Crest,the Resistance stronghold in the French Alps,run by Luc,Renard and Rex,the parish priest. Faith takes over from Cad and recruits two new agents,Virginia Mitchell,who lived in France and has a French ex-husband and actor Lewis Lake. Kit and Renard are summoned to London and asked to organize a local uprising as a diversion for an invasion though Kit is not enthusiastic to risk his colleagues' lives. Nicole proves to be a spy for Stuckler.

Faith is appalled to learn that the planned revolt will have no military backing and is purely a diversion,which will result in many partisan deaths. In Le Crest,however,the blissfully unaware Maquis plan their uprising. Luc tells Emily he is sure Nicole is the traitor but Nicole makes sure she is seen as a saviour when she alerts Emily to a German weapon search.

Rex goes into hiding,unaware that Stuckler will order reprisals if he is not recaptured. Emily and Luc declare their feelings for each other whilst Virginia,trailed by a suspicious Lewis,visits ex-husband Philippe,though she fails to get him on side.

Twenty villagers from Courmont are killed in reprisal for Rex,who renounces God and quits the church. Whilst Emily has to break it to Kit and Renard that the uprising must be aborted,Faith and Gordon desperately plead for military back-up from the War Office,only to be told that all resources are needed for the Normandy landing.Philippe,meanwhile,appalled by the massacre,confronts Stuckler though the meeting is interrupted by Rex,who kills several German soldiers before being shot himself.

Having forced Sylvie to tell him of the set-up at Le Crest Stuckler shoots her and her mother. The previously complacent Philippe,appalled by the brutality,agrees to spy for Virginia and tricks Stuckler into divulging the German plan of attack on Le Crest but before he can tell Virginia Renard,unaware that he has changed sides, abducts him as a hostage.

Interrogated by Renard Philippe says nothing but Virginia divulges their relationship. Already angry to think that no Allied support will be forthcoming to combat the expected German air strike,Renard orders them both to be shot along with Nicole. However Stuckler ,unaware of Philippe's change of heart,has captured Renard's family and forces an exchange with them for Philippe whilst Virginia must prove her loyalty by killing Nicole

Emily and Luc make it back to Le Crest,where Liz has just arrived but Lewis and Kit are both caught by the Germans and Kit is tortured. Philippe,using his position as prefect of police,takes advantage of Stuckler's absence to order their release but Kit is too ill to travel and only Lewis and Philippe make it back,Stuckler now aware that Philippe has gone over to the Maquis.

German paratroopers swarm all over Le Crest,forcing the Maquis into hiding in the woods. Brave woman doctor Bosco,Nicole,Philippe and Max's son Jean-Louis are among the casualties. The British agents and Renard and his family manage to get back to the town of Beaufort,where Liz is able to rescue Kit from the firing squad though Emily and Luc are less fortunate and Renard kills Stuckler to avenge them.