Two inhabitants of the planet Nistasium, Xenoi and Pidé, want to prove themselves through an interplanetary mission. Upon volunteering, they are assigned a mission on planet Earth, with the simple assignment of offering an invitation to Earthlings to be inhabitants of Nistasium, because humans will inevitably self-destruct. When they fell on our planet, it quickly turns sour. Apparently the database on planet Earth was not as complete and up-to-date as they believed.