The Shadow Network takes us back to the world of WW2 espionage that she introduced in The Silk Code. This story features Neil Callaghan from the earlier book but it is a separate story about a different aspect of Britain’s secret war against Germany. It centres on the work of the Political Warfare Executive which pumped out black propaganda to the Reich. It was a significant part of the British war effort, pioneering tactics that we see used in conflicts nowadays. It’s fascinating stuff and deserves to be better known. Swift, as ever, writes with authority and I loved those parts of the book.

The social background to the story also gives vivid insights into the world of the time. The heroine, Lilli Bergen, is a half-Jewish German, who we first meet living in Berlin. Swift gives some idea of the reality of life for Jews at the time. Lilli’s (non-Jewish) father disappears into the camps – her mother is already dead – and Lilli flees to Britain. There, she thinks she is safe until she is caught up in the anti-German hysteria that saw Jewish refugees rounded up alongside Nazi sympathisers and interned on the Isle of Man. Swift catches the terror of Jews who had lived under a police state being suddenly ordered from their homes to live, without family or friends, behind barbed wire.

Fortunately for Lilli, the Political Warfare Executive needs a German singer to entertain on a radio show designed to appeal to German soldiers. The songs are interspersed with propaganda designed to undermine morale.

In her new job she meets an old boyfriend from Germany – somebody she believes to be a Nazi collaborator. Instead of denouncing him to the police, she decides to investigate on her own. It’s a trope of this sort of fiction (one I’ve been accused of myself) that your hero will find themselves in a situation where they have to undertake a risky job without any kind of backup, although they are surrounded by people who could easily help them. Swift does a good job of explaining why Lilli insists on becoming a (frankly unconvincing) Mata Hari even when she has clear evidence that her ex-boyfriend is a wrong ’un, but I did struggle to suspend my disbelief. I had particular problems when she gets engaged to the villain and moves in with him. I know it was wartime and that people let things slip a little, but I was surprised that nobody seems to have thought this was odd. What, to me, was even odder was that, though the man is a cad and a bounder, he accepts that they will share a bedroom without actually having sex. That’s a necessary plot device, as there is a romantic subplot in which Lilli is saving herself for her true love.

Will Lilli save the day and will her apparent philandering be forgiven? No plot spoilers here, but no great surprises in the book either.

Like all Deborah Swift’s books, this is a joy to read and the story bowls along fast enough to skim over the more implausible elements – and you learn a lot about the war years on the way. ( )