The historical center of the ancient city of Velikiy Guslyar is under attack - in order to build a highway, it was decided to demolish several architectural monuments. Only a miracle or... the invention of an anti-gravity method of moving buildings can preserve the appearance of the city. Professor Mintz sends Korneliy Udalov to a parallel reality to his double, who has succeeded in solving the problem of gravity. You will learn about the adventures of Cornelius in his prosperous native Guslyar and its deteriorated copy from the story “The Perpendicular World” and other stories in the collection.