Ilya was an ordinary engineer - he studied all his life, believed that he knew how stars are born and die, how to build an airplane and how to start a chain reaction. But one day he found himself in another world, on another planet, where the descendants of people who fell there back in the Neolithic. There he discovered something that was destroying his picture of the world - magic. He is convinced that two riddles, two secrets - his transfer to another world and magic - must have something in common. He believes that, having unraveled the mystery of magic, he will be able to return home.