According to the plot of the book, Foma Hryhorovych tells the story of how his grandfather was sent with a letter to the queen. On the way, the grandfather met a Cossack, and he confessed to him that he had sold his soul to the devil and that same night will have to pay. Grandfather decides to help him and chats all night, but his sleep overwhelms him and he falls asleep. Waking up, the grandfather realizes that his plan failed and, moreover, disappeared not only the Cossacks, but also the horse and his hat, where he put his diploma for the queen. Not knowing what to do, the grandfather goes to the pub, where he is advised how to find the devil and ask for his diploma back. Thus begins the journey of his grandfather on his diploma, as a result of which he goes to hell, where he meets witches, devils and other monsters.