Albert and Lisa continue to be suspicious of Curtis, whilst Lifeline is stretched to its limit trying to deal with several evaders. The Germans capture one evader, Sergeant Walker, who has travelled down the line and is familiar with several of Lifeline’s personnel. Walker makes a desperate bid for freedom to avoid talking and throws himself down a staircase at Gestapo headquarters. As Walker recovers in hospital, Lifeline deliberate over whether he can be rescued from the Germans or if he must be silenced to preserve the security of the line.

An American airman has written a magazine article about his experiences being shot down in Europe and getting back home with the help of the evasion lines. British Intelligence has blocked the article’s publication, but Brandt has managed to obtain a copy from German intelligence based in America. Studying the article, he begins to deduce the probable route taken during the evasion and travels to the Pyrenees, where he enlists the aid of Malaud, a French policeman, to close in on the line. Meanwhile, Lisa is also in the area, taking some evaders down the very route Brandt is so close to tracking down.

When Lisa Colbert is arrested whilst meeting a contact near Paris, the whole future of Lifeline is put at risk. This also leads to her uncle being arrested and interrogated by Kessler. Whilst in prison, Lisa must decide whether she can trust her fellow inmates who claim to know who she is and how they can help her escape. These events will lead to tragedy, both personal and for Lifeline.

With so many evaders, Lifeline’s resources are once more stretched to the limit and they must watch their backs after recent events. Jacques and Natalie are dispatched to check out a young South African evader, Noel Uys, and have to consider eliminating him when his answers to their questions fail to satisfy either them or London. In desperation to survive, Uys overpowers Jacques and armed with a shotgun, takes Natalie as his hostage.

The citizens of Brussels are ordered to celebrate the Fuhrer’s impending birthday, and Albert and the others are suspected of being collaborators when they must hang a Nazi flag outside the Candide. Meanwhile, a man claiming to be an RAF evader approaches Catherine Bidout, an elderly English woman who has not yet been interned by the Germans. Rumours of a British woman in Brussels hiding an evader reaches the Candide and Albert decides to investigate. Madame Bidout is uneasy about the risks she is taking and contacts an old friend – Brandt – for help. However, the evader is a plant placed by Kessler to entrap Lifeline and now Brandt is also in danger.

Curtis’ cover has been blown and Kessler knows that he is part of the resistance. To avoid endangering the others, Curtis goes to ground in Brussels. Knowing that Lifeline is at last in his sights, Kessler orders that all routes out of the city are blocked and co-ordinates a house-to-house search throughout the city. In desperation, Curtis goes to the Candide to ask for help, and Monique comes up with a highly audacious escape plan.

Lifeline must work overtime when a heavy storm downs several British planes on their way back from a bombing raid on Berlin. Natalie comes into contact with Major Nicholas Bradley, a British officer on a special assignment, who is uncooperative and highly critical of Lifeline’s security when he follows her all the way back to the Candide. It seems that Bradley’s concern is well founded, as an undercover Gestapo man is also tailing Natalie.

Natalie’s new boyfriend, Francois, is keen to become involved in Lifeline, but Albert has doubts. Paul Vercors, the fanatical leader of a Communist cell in Brussels, wants to take over Lifeline, and tries to enlist the assistance of a colleague – Max. Meanwhile, the Communists continue their resistance activities and plant explosives on a railway line to derail a train. Unfortunately, the train’s passengers include Natalie and Francois, escorting evaders down the line.

Lifeline’s original function is now over – the Allied advance has severed the evasion lines and it is now a matter of keeping evaders safely hidden until the war is over. Despite Kessler’s irritation at Reinhardt’s manner and methods, his efforts pay dividends when he discovers a Lifeline safehouse. Two of his new prisoners commit suicide rather than talk, but Reinhardt is determined that the third prisoner will give information under torture. Albert and Monique receive a tip-off that the middle-aged Chantal sisters, who are based in Senlis and often shelter airmen for Lifeline, are in imminent danger.

Vercors has taken Albert, Monique and Reinhardt prisoner, and plans to hang Albert as a collaborator and a murderer. Only the Allies, helped by Natalie, can save him but they have only just entered Brussels. Meanwhile, Kessler and Madeleine are trekking on foot towards Germany through the Belgian countryside. To evade capture by the Allies, Kessler decides to take on a new identity.