In the country of the Three Fat Men revolutionary situation - dissatisfaction with the poor section of society, trying to raise a rebellion. Ideological mastermind of the revolutionaries are gunsmith Prospero and gymnast Tibul. One of the main characters of the novel, a scientist, Dr. Gaspar Arneri sympathized with people, even though the - fairly wealthy person. Prospero arrested and put in a cage zoo, tightrope walker Tibul but remains at large. Dr. Gaspar hides Tibul in his house and repaint him in a Negro. The next day, "Negro" learns about underground passage from the Palace of the Three Fat Men (the secret was opened to Tibul by a seller of balloons, who on the eve of accidentally drifted by the wind on the palace kitchen). Meanwhile, guards mutinied palace guards inject by sabers a wonderful doll of prince Tutti, who was looking similar to live girl and doctor Arneri was ordered to fix a doll for one night under threat of severe punishment. He can not do that due to objective reasons and carries a doll to the palace, but on the way it loses. Looking doll he finds in a van wandering entertainers a circus girl Swauk as two drops of water like a broken doll. At the initiative of Tibul, she agrees to replace a doll and help the revolutionaries: save Prospero and help him to escape from palace. The girl manages it: Prospero escapes from the palace through an underground passage but Swauk caught and sentenced to death. Nevertheless, everything for her and revolutionaries going well: the guards, sided with the people, replaced Swauk with original doll and revolutionaries managed to topple the power of Three Fat Men.