Who?
The main characters are all varmints, which is a creature that looks similar to dogs. Some of them are large and some of them are small.
What is happening?
The story starts in a very peaceful world. One of the varmints was sitting on a green glass with a beautiful tree beside him. But all the sudden, gray sky comes over and destructs and pollutes nature. The varmints suffer both mentally and physically and some of them even dies on streets.
When?
It doesn't seem to be too old of a story. I feel like it represents the situation in our recent society with growing industrialization. I would say the sometime in last 50 years.
Where
The story takes place in a mysterious industrialized city where humans doesn't exist. I
Why is this happening?
In this occasion, the varmints are not making their effort to keep the earth clean. Instead, they do whatever they want which causes pollution. It accurately shows the human civilization in a way that people are too worried about themselves and not focusing on how they can contribute to their society.
How does it end?
Tons of jellyfish came flying into the city and brings back the beautiful nature.
What is the theme?
The theme of the story is that people are so self-centered. We are constantly destroying the environment and this story is to make people realize that. Earth in reality is a much better place and we haven't seen it because of the human activities.