It’s set on a spaceship. The Earth is either destroyed or uninhabitable, and humanity has survived in space. They have population policy on the space station where they live, no more than one child. A woman has two daughters, one of them keeps in her room for years. She was hiding under the panel on the floor of the room when the guards came to check on it. Then he was secretly coming out. Later on, the film caused an oxygen problem, and to reduce the population, they chose some of the lower classes of people they had chosen and threw them into a mass sleep and thrown them out of the ship.