Monique is the barmaid embroiled in an affair with Albert. She works at his café, which means they're in painfully close proximity every day. Monique isn't merely a mistress, though. She's also a secret agent within the Lifeline network, so they must balance their forbidden liaisons with their even more forbidden resistance work. Monique also happens to detest Albert's invalid wife, and is hoping to persuade him to leave her once and for all.
Meanwhile, over on the other side of things, we have Ludwig Kessler, a much-feared operative within the Gestapo. He is dispatched to Brussels by Nazi High Command for the very specific purpose of exposing and smashing the Lifeline network. Unbendingly devoted to the Nazi cause, Kessler is a cold and formidable enemy, and his uncompromising attitude even puts him at loggerheads with the local Luftwaffe officers. The fact that Kessler can be paranoid and defensive makes him all the more dangerous.
Kessler's arrival in Brussels is bad news for Lifeline, but don't go expecting Erwin Brandt of the Luftwaffe to exactly welcome him with open arms either. Brandt was tasked with dealing with Lifeline, but his superiors in Berlin are dissatisfied with his work - hence the unexpected arrival of Kessler to "assist" him in beating down the resistance. Brandt, being in the Luftwaffe rather than the Gestapo, is considerably less hard-edged than Kessler, and actually treats captured airmen with a measure of decency and respect. But will Kessler's dark presence change things?
Flight Lieutenant John Curtis has reason to be grateful to Lifeline. He himself was smuggled to safety after being dropped into Europe, and now he's been sent back to Brussels to help coordinate the network. This doesn't go down too well with some resistance agents, including Lisa Colbert, who treats him with suspicion and even hostility. Not that that stops Curtis from developing a clear romantic attraction to the fiery resistance fighter. It also doesn't help that Curtis' presence may prove a liability when the Nazis start getting wind of things...
Young, beautiful Lisa Colbert seems like an ordinary Belgian citizen, trying to get by in the midst of the titanic conflict which has engulfed the continent. Yet all is not as it seems. This medical worker is secretly the founder of Lifeline, a covert organization which works against desperate odds to help stranded Allied airmen escape Nazi-occupied Europe. Headstrong and fiercely determined, she will risk everything to help the soldiers get back to Britain, even if that means clashing with fellow rebels, and even with official agents sent over by Britain to help run Lifeline.
On the face of it, Albert Foiret is a most unlikely rebel. Decked out in white shirt and waistcoat, this middle-aged café owner looks like a placid chap seeing out the war in his own quiet way. In fact, he plays a key role in Lifeline, working alongside Lisa Colbert to help the airmen. Possessing an iron will, Albert can be cold and calculating, and he is also carrying on an illicit affair with a barmaid. Meanwhile, he also has a wife he's no longer in love with, who is laid up in bed due to a crippling injury, and is under no illusions about her husband's behaviour.