Under the Poisonous Fog

A sudden gray tide engulfed the entire city. The emergency doctor woke up in the poisonous fog and was taken into Area S of the underground shelter. Area S seems perfect - there is food, lights, and order. But Shen Mo soon discovered that the people here were divided into three, six or nine grades, and the "unqualified ones" were sent to deep purification areas to undergo genetic modification. The success rate is 23.7%. Losers are always silent. When Shen Shen saw his former colleague in the purification area - a woman with dead eyes, he knew: this is not only a matter of survival, but a matter of choice. Obey the rules and stay alive. Break the rules and die. Or - find a third way.