I was hoping to have in my hands a good historical spy-tale and instead this book is a bang of incredible nonsense, that shows how the fantasy unsupported by a minimum of historical research does not serve anything, to live close to the facts intended to fiction does not help, if these facts are not known to you and that trying to take a superhuman as a protagonist can only make the narration boring.
So, between a Italy, a France and a Germany straight out of a operetta, weapons of mass destruction worthy of Jules Verne and a female protagonist who seems to be suffering from acute schizophrenia, the novel drags wearily towards the end, and you read it just hoping for a last-minute stroke, which, unfortunately, does not arrive.
Two stars because the cover is very beautiful.
I thank British Library and Netgalley for giving me a free copy in exchange for an honest review.

The appeal of this novel is lost on me - Is there a golf, ridiculous descriptions of women, shady and powerful men, and a super weapon? Yes, but the plot is a horrible mess, the dialogue is embarrassing, the descriptions of (then) exotic locales is terrible, and the main character even more of a cipher than can be forgiven. A hard pass on this one.