Nova bears Ulysse a son, Sirius, who walks and talks at three months. Fearing for their lives, they take the place of the human test subjects in a space flight experiment. Because all humans look alike to apes, they are able to escape without notice and they rendezvous with the orbiting ship. Ulysse programs the ship back to Earth. As they fly over Paris, Orly Airport and the Eiffel Tower look the same. When they land, however, they are greeted by a field officer in a Jeep who is a gorilla. It is subsequently revealed, via the frame story, that Jinn and Phyllis are actually civilized chimpanzees, and they discard Ulysse's story as sheer fantasy because they find the idea of intelligent humans unbelievable.