In the center of the science fiction novel is the fate of the talented scientist Artamontsev, who is engaged in research into the nature of Space-Time. The reader gets to know the scientist during his work at Interpol. The International Agency for the Study of Global Problems (IAG), whose range of interests was related to the problem of Space-Time, became interested in his activities. The President of the Agency invites Artamontsev to work, to which the scientist makes a significant contribution by creating a new technical solution for a device for moving in Time. Artamontsev becomes the first bichronaut of the planet, a person launched into Space-Time. He finds himself in the 14th century. While the bichronaut was there, 25 years passed in the 20th century. His body, naturally, could not be preserved. The scientist returns to Earth in a different guise...