I find it easy, when reviewing Manda Scott’s books, to run out of superlatives. I have never yet been disappointed in any of her body of work and if you are a fan of historical fiction and have not yet encountered her books, then don’t waste time here. Go buy one and get reading.

Three years ago, I read her book Into the Fire with raw, new interest, for she had turned from the milieu of ancient Rome and created a tale in a dual timeline that linked the campaigns of Jeanne d’Arc with a modern police procedural thriller. Into the Fire was my book of the year and I remember badgering her, asking when she was planning on a second book, and simultaneously wondering how on earth she could achieve such a thing.

Then, as something of a side-shot here, last year I read Kate Quinn’s vaunted and most excellent Alice Network, which was similarly my book of the year last year. That novel is a dual timeline work too, set in Post-war France and during the First World War and delving into the world of women spies.

So along comes A Treachery of Spies. And, for me, though it’s only August, it seems clear this is going to be my book of this year. While the novel can be read as a standalone and is not reliant upon the reader having finished Into The Fire, it certainly adds something to have done so, for it explains in depth the motivations and history of the main modern character, Ines Picaud, and a few of her supporting cast. This is not a sequel to that book but more of a second tale, independent and glorious in its own right.

Treachery involves once more a police investigation in modern Orleans, this time into a mysterious death – the body of an old woman found in a car park with a very specific grouping of gunshots and post-mortem mutilation. And while the first book simultaneously led us around France in the retinue of the Maid of Orleans, this one delves into French resistance activity during the height of the Second World War. This, then, is the best of books for me, for it feels a little like what would happen if those two favourite books of mine had met.

The story is one of suspicion, betrayal, murder and espionage on a truly epic scale, telling the tale of spies trained by the British and dropped into France to aid the resistance, of their handlers, the intricacies of coded communications and the-so-called Jedburgh operatives sent over around the time of the invasion of Normandy to aid the resistance in their work. It is also the tale of Picaut’s investigation into an increasingly dangerous series of attacks that has a complex and hidden connection to the survivors of that world of wartime horror. One central theme that helps define the plot is that of revenge, combined with a strong sense of brother- and sisterhood. The heroes of wartime France form bonds that will last ’til death, no matter what the future holds, and similarly some actions leave a call for revenge that echoes through the years.

For the sake of avoiding spoilers, I won’t delve into plot specifics any further. What I will do is say that I cannot conceive of how Scott began to piece together this complex and twisting tale, and that when I read a novel with any kind of mystery element I constantly attempt to solve the puzzles as I go. Sometimes I unwrap the plot early. Sometimes I manage parts of it. With this book, I remained uncertain to the very end, and even the one thing I did anticipate I constantly found myself doubting. That is a good sign for a thriller in my opinion.

Scott continues her excellent portrayal of the world of modern French policing, but here she also shows a great understanding of the world of wartime espionage and of occupied France. The world she builds for the reader is flawless in its realism and vibrant and terrifying throughout. But despite a strong plot, beautiful prose and a vivid environment, for me it is her characters that stand out. From the beginning it seems we are focused on one historical character for point of view, but as the tale unfolds we are treated to more than one insight, and each character she builds for the reader is real and true.

And as the narrative moves to a close, we are introduced to a concept that is both chilling and horribly current and relevant. In this, I can only salute Scott. A Treachery of Spies is, then, a masterpiece, which is what I’ve come to expect from the author. The two problems she creates are: setting herself such a high bar to leap with her next book, and making me wait now before I get to read it.

Bravo. Treachery is out tomorrow. Pre-order it now or go out and buy it tomorrow.