"Co-author" is a philosophical novel by the famous Ukrainian writer Yury Andruhovych, which tells about the mysterious life of the famous poet Viktor Aldon Yan, who is famous for his incredible image and creativity. The main character constantly lives in two realities - his real life reality and the imaginary world that he himself created in his head. Feelings of fantasy and reality are mixed in the work, creating a unique atmosphere of mysticism and mystery. The reader travels with the main character in his fantastic world, where the images are constantly changing, unraveling and intertwining again. "Co-author" is a book that will not only entertain you with its interesting story, but also make you think about reality and fantasy, between which there is a fine line.