The book begins with a story about the dramatic history of the search for ways to unlimitedly extend human life, the search for immortality. However, the memories of people who died and were brought back to life bring unexpected evidence: human individuality, his “I” continues to exist independently of the body, apart from it. These properties unexpectedly come into contact with stories about posthumous ghosts and lifetime doubles. Science has begun to study this phenomenon; instruments have already been created that detect the presence of such field structures that are not usually perceived by our vision. The first contours of their images were obtained. No less convincing material evidence has been obtained regarding the poltergeist, the “noisy spirit.” The inaccessible, but real world of subtle intelligent beings invisible to us is next to us. The book, written solely on the basis of evidence and facts, gives reason to ask the question: isn’t a person, in some of his states, one of the subtle incorporeal entities from “rarefied matter” (K. E. Tsiolkovsky) inhabiting our world? The book is intended for a wide range of readers.