The friendship of a student of Mechanics and Mathematics at Moscow State University with the brilliant mathematician and philosopher Apolonych at first looked harmless. But as the young student is seduced by the ideas of his older friend, philosophical debates in an intellectual apartment near Moscow turn into a mental test for both. While for one philosophy is a youthful pastime of the mind, for another it is life itself. Apolonych is confident that he has a great secret that can change the course of world history, but a mystical coincidence of circumstances will prevent the secret from coming out...