The two main characters of another comic series by Goscinny, "Iznogoud", begin to take shape in the episode when Nicolas is in summer camp. He and the other children are forced to take a nap, so the conselor tells them a story about ""a caliph who was a very good man but who had a very evil vizier..."", then tells how the caliph dresses as a common man to find out what people think of him, and the evil vizier takes his place.