M. Bykova reflects on animals unknown to science, on the inexplicable phenomena of nature, on many other things that concern people of our days. She invites the reader on a journey for mystery. Who is he, "Bigfoot"? Is our ancestor or Neanderthal, a higher monkey or a completely unknown creature? Does he live in some kind of ecological niche, or, hiding, invisibly coexists next to a person throughout his history? The famous cryptozoologist Maya Bykova reflects on these questions in her book. In addition, the issues of the existence of other animals unknown to science and various inexplicable phenomena of nature are touched upon.