This story happens in almost four hundred years later. With the development of technology, the destruction of human to our earth is instantly increasing. The cloud is too thick to let light pass through. Therefore the world is divided into two parts. Below the cloud, there is no daylight. However, above the cloud, the sun still rises in the morning and sets in the evening, as it does now. In order to pursue the sun, people have built a city in the sky above the cloud. However, due to the limited resources, only a few people can live above the cloud. According to social status, those who have high social position, such as aristocrats, business tycoons and political elites, called A-Level can live in the city above the cloud. And the others who have low social position such as farmers and workers remain below the cloud. According to this background, what is our life going to be if we lose the daylight? What does daylight turn to be after disappearing so many years? What will happen if daylight show up again? The project will show you the answers. Enjoy the story.