The main action of the story takes place 2.5 years after the events in Sunny City.
Znayka in the company of Herring and Fuchsia (inhabitants of the Sun City) visited the Moon, after which he wanted to fly there himself. Steklyashkin and some of the inhabitants of the Flower City were also interested in this idea. Znayka expressed his assumptions about the origin of craters on the moon, as a result of the pancake theory (except for it there were meteorite and volcanic theories). He was sure that people could live under the surface of the moon. Most of them considered the theory of Znaykaokhibochnoy. During his first flight to the moon Znayka took with him a piece of lunar soil, from which the light went out at night. An interesting incident is associated with this stone: when Znayka put it next to the magnet, then the house disappeared gravity. Very funny was the adaptation of shorties to weightlessness, they even cooked dinner. After they found out the cause of the weightlessness,
respect returned to Znayka. When the weightlessness device was studied by shorties, they began to prepare for a flight to the moon. Donut and Dunno were not included in the team that will fly to the moon, so they climbed into the night in a rocket and accidentally pressed the power button. So they were on the moon. Arriving on the moon and dressing up the suits, they went to explore the moon. Neznayka was inside the moon, falling into the tunnel.
All the plants on the Moon were small. Hungry, Neznaika went to a cafe where he was asked to pay for food, but he did not have them. Therefore, he got into a catastrophe. On the Moon was an unusual system for sorting criminals: they were sorted by the size of the head, nose, by their height, etc. Neznaika was mistaken for a thief. In prison, he learns about the money, the laws of the Lunar Society and the Idiot’s Island, where all the criminals of the Moon are, who there become sheep. Dunno, in turn, told about the Earth and huge vegetables. He was not taken seriously. In prison, Neznayka met Kozlik, along with whom he was released. A moment, a new acquaintance
of Neznaika, asks for a message. Neznayka, along with Kozlik, visit Joliot to give him a letter. Neznayka, Mig, Kozlik and Julio decided to create a joint stock company of huge plants, to get to the surface of the moon and bring back seeds of huge plants. Around Neznaika create an artificial excitement, in order to improve the sale of shares. Shares are popular, but only among the poor who buy them for the last money. One rich man, Sprutts, was very interested in society: if the joint-stock company does not stop its work, then it will go bankrupt. He makes an offer to the members of society: he gives them money, and they run away from the city. Julio and Mig accepted the proposal of Sprutts. Neznayka and Kazlik flee the city: everyone learned about the bankruptcy of the joint-stock company. They move, live in cheap hotels, similar to prisons, work wherever possible. Subsequently, Kozlik falls ill. That’s why Neznaika gets a job as a dog sitter. But then the unknown also loses this job: the mistress of expensive dogs will find out. that her dogs were in a dirty hotel. As a result, Neznayka and Kozlik find themselves on the Duratsky Island, where the signs of a sheep appear at Kozlik.
After Neznaika got into the tunnel, Donut remained on the surface of the Moon, but when the food in the rocket ended, he went to look for Dunno. Donut came to the shore of the salt sea, but the inhabitants of the coast did not eat it. He opens his business: he begins to sell salt. But local rich people begin to lower prices, so that small merchants go bankrupt. Then Donut has to twist the ferris wheel, which used to be very fond of. In a new job, he meets members of society who buy newspapers. books and talk on smart topics. Donut enters this society.
Discovering the disappearance of the rocket, the shorties begin to build a new rocket, multi-stage. Znayka and other residents of the Flower City go in search of missing friends. The rich from the moon order the police to open fire on the rocket: they do not want the arrival of the astronauts. Znayka and his friends use weightlessness to save themselves from bullets. They, after learning about the society of giant plants, distribute seeds to the poor of the Moon. To protect themselves from police, poor people are given zero-gravity devices. Donut, after learning about the arrival of the rocket, understands that this is Znaika and the inhabitants of the Flower City and goes to them. At this time in the city there is a socialist revolution, as a result of which the rich are forced to work with everyone. After the meeting Znayka and Donut they go to the Foolish Island to pick up Dunno. Shorty lucky. Neznaika has not yet turned into a sheep, but he yearns for his home. Therefore, it urgently needs to be sent to Earth, but Sprutts and Julio blow up the rocket. However, the znayka and his friends use the old missile and leave the Moon. Having got to the Earth, Neznaika recovered. That’s what a short man was Dunno.