The protagonist of this novel is the Square, living in a flat country - Flatland. After a lengthy account of customs and social hierarchy, Kvadrat tells about a dream in which he saw the one-dimensional country of Lainland and communicated with its king. Every millennium, a voluminous world comes into contact with a flat world. On the threshold of 2000, the Sphere is the Square and introduces it to three-dimensional space. At the same time, a law was passed in Flatland, according to which everyone who talks about the world outside is recognized as heretics and subject to execution or imprisonment, depending on its social status. The square is eager to share new knowledge, but is forced to hide. In the end, one day he voices his beliefs out loud and is put in jail, where he wrote this novel.
