Hundreds of volumes have been written about yoga, but this small book by G. Boreev is different from all the others. The author independently walked the path of the student and spoke in detail about his experience of reaching Samadhi. The secret laws of subtle worlds are revealed here, the secrets of Kriya yoga exercises, Karma yoga and Yoga mantra are sincerely described. Various explanations and cautions are given to practitioners. Techniques from the first and second parts of the book lead to conscious exits from the physical body. Many of them are published for the first time.