A mournful Prince recently come into power after his dead Grandmother has died, cannot smile. His portly Prime Minister engages the attentions of a discarded Giant Parrot (disguised as a Scientist) to generate a smile. various types of smile are identified before a young beauty who lusted after the Prince appears to demonstrate a "Loving Smile"

Gnoli uses an interesting device to show the main characters by deploying them in a tree right at the beginning. The book ends with a remarkable balloon flight.