Dystopian sci-fi about an over-populated world in which the solution has been to program people to operate solely in either day or night, meaning that the population are only conscious half the day and can never interact with each other.

Overpopulation makes coexistence impossible in the planet. Then, the Government developed an enzyme implanted in the DNA of the population that regulate their bodies by the light of the sun or by the darkness of the night making some citizens of the day and other of the night.

When the over-population made coexistence impossible, the Government decided to divide the population by implanting an enzyme into peoples DNA. Hence, all humans are now regulated by solar light and darkness, transforming people into day or night inhabitants.