Not all wars are won on battlefields. And not always do victories come with banners and the thunder of artillery. Sometimes, to win a war, you only need to stop a small group of people who direct the whole process. But to do that, you must at least know your enemy lurking in plain sight.
And so, people who have been carried back into the distant past have to apply in practice what they once read in books. Even if among them there are no true aces of secret war, on their side are an analytical mind and a memory of what happened. They need very convincing arguments so that even the suspicious Emperor Paul will listen to their words… And the vaunted British intelligence service, accustomed to moving inconvenient people around like chess pieces, suddenly finds in front of itself an unknown but very dangerous enemy—an invisible and elusive one. Behind him looms the ghost of an old, experienced foe: a general of the Spanish army, known by the nickname “The Night Guest.”