The heroes of the book strive to understand the structure of the Universe and make the world around them better. The main character of the book is a neurophysiologist. The heroes were fortunate to live in two worlds at once: in a world that exists on the principles of cause-and-effect relationships and a world where the main condition for its existence is His Majesty chance. The heroes experience many adventures, including life-threatening ones, but always come out of the situations generated by these worlds with dignity. As a result, our heroes discover many secrets of the Universe, which allow them and the whole society to look at the future fate of civilization with optimism. For ease of reading, all three parts of the book are here.