The author summarizes materials on a controversial and fantastic phenomenon - sexual contacts of people with representatives of other worlds, and perhaps extraterrestrial civilizations (in ufological terminology - “contacts of the 6th kind”). Ten years ago, no one believed in this, researchers of the phenomenon were subjected to ridicule, and victims of violence were clearly diagnosed with sexual pathology. As a researcher of anomalous phenomena, the author encountered this problem many years ago. The book provides interesting and reliable data about certain experiments on people in the field of sex and reproductive production. The author strives to explore this problem from a serious scientific position and is far from speculative and sensational fabrications. The book is useful and educational and is addressed to a wide range of inquisitive readers.