I don't know when all the water resources on the earth have been polluted. People who drink this water will die of illness within a few days, and the causes vary. Seeing the world's population plummeting as a result, human scientists are still powerless, so they extend their survival hands to the vast universe.
On an unnamed planet, humans found an alien creature that could purify water and was non-aggressive. They were transported to scientific research bases for research as an antidote to the earth. It was also during this period that Jiang Qingyuan, a lonely young man who lost all his friends due to the disaster, met the gentle Experimental Subject No. 013. The good times did not last long. After Jiang Qingyuan got his wish and became one of the researchers at the scientific research base, he got a more intuitive glimpse of human selfishness and ruthlessness. For the sake of scientific research, he had to dismember his friends who had been accompanying him over and over again. Jiang Qingyuan could no longer bear it, and he decided to escape with No. 013.
An invasion conspiracy that spanned several years quietly kicked off at this time...
Concept: Darkness is always hidden in the surface