The tenth book of the Small Row is dedicated to the history of the late 18th century - the era of Pugachev and Suvorov. It would seem that such a recent story, just 200 years ago, cannot contain anything unexpected. However, this is not the case. It turns out that it is the end of the XVIII century that hides in itself. in fact, the main mystery of recent history. Having realized which, we begin to understand, for example, why today it is believed that historians of the XVIII century "were mistaken in many ways," and their descendants, historians of the XIX century, already "knew everything correctly." And also understand a lot more in recent history. The book does not require special knowledge and is intended for anyone interested in applying mathematics to uncover the mysteries of our history.