Years ago, I remember reading reviews of a new film that sounded intriguing called The Return of Martin Guerre, though as it happened I never actually saw the film. At the same time, I remember being puzzled that something in the plot seemed familiar to me, though I couldn’t work out why that might be so.

Flash forward 30-odd years and I am reading Assignment in Brittany by Helen MacInnes, or rather, re-reading. I don’t specifically remember reading this novel before, but in the late-60s and early-70s I went through a phase of reading everything by MacInnes that I could get my hands on, and this was one of her more prominent titles so I would be surprised if I hadn’t encountered it.

And as I read the novel I begin to realise what it was I recognised in the plot of Martin Guerre.

Assignment in Brittany was her second novel, published in 1942. It is a spy story (of course) set in Brittany shortly after Dunkirk in the early days of the German occupation. A French soldier, rescued from Dunkirk, makes his way cross-country to his little family farm just outside a small Breton village. But he isn’t a French soldier; he’s an English agent who happens to look enough like the Frenchman to take his place, allowing him an ideal opportunity to observe German preparations throughout the region. To make the deception work, he has to fool the Frenchman’s invalid mother, his fiancee, and the old family servant. For a while this seems to work, but soon enough suspicions start to emerge, mostly because the Englishman is nicer than the Frenchman was.

The nastiness of the Frenchman soon takes an important turn as the English agent, Martin Hearne, gradually comes to realise that the Frenchman, Bertrand Corlay, was actually a leading voice in a Breton nationalist movement that was being subverted by the Germans for their own ends. Indeed, Corlay was a willing agent of the Nazis, giving Hearne an unexpected opportunity to play a dangerous double game. But the only way to do that is to step out from behind his disguise to those closest to Corlay.

It is an extraordinary novel for its time. It must have been written in the immediate aftermath of Dunkirk when there was considerable confusion about German plans and British capabilities. In the novel, MacInnes imagines the Germans building military airfields across the Breton plain in order to launch an aerial bombardment of South West England; a plan foiled by the intelligence Hearne provides. I’m not sure if that was ever really the German plan, their activities in Brittany seem to have been primarily naval, directed towards bases used for the Atlantic war, but in the heat of that particular moment it was probably a reasonable expectation.

More interesting is the care with which she portrays the experience of rural France under German occupation, an experience about which she is likely to have heard whispers at best. And the novel is full of an intimate knowledge of the geography of the region, something that would become a hallmark of her postwar spy fiction. There is a sense that this is an area well known to the author, a sense that these stones, these roads, these dusty tracks, these fields can be found on the ground exactly as they appear in the novel. This sense of place is something that would be a distinguishing characteristic of her work, though it is interesting to see it in place here when she couldn’t arrange a quick research trip in the middle of writing.

The other regular characteristic of her work is here also: the handsome, charming, engaging hero figure, and the love interest who proves herself at least as brave and at least as resourceful as the hero.

And so we have the basic Martin Guerre plot (40 years before the Martin Guerre film): a returning soldier who isn’t, who is taken in without question by those closest to the original, but whose identity is eventually exposed by the fact that he is nicer than the original. But MacInnes uses this as the basis for a tale that involves duplicity and betrayal, violence, revenge, capture and escape. A quiet story of high action.

There was, apparently, a film made of Assignment in Brittany, but I know I’ve never seen that.