In the fourth year of the gray tide, water can kill people, medicine can induce mutations, and survival often relies on gambling.
Quarantine officer Gu Yan could see another scene——
A dying dog has three evolutionary branches;
In a pool of highly poisonous water, there is moss that can eat up the poison;
An invulnerable thug with all his strength tied to a few materials that could break at any moment.
He can see the road, but he can't save the cost for anyone.
When Black Sail, who controlled the water purification plant, demanded that living people be exchanged for water, Gu Yan led forty-three survivors and set up a white tower in the abandoned animal quarantine: making his own water, guarding the gate by himself, and letting everyone who received evolutionary intervention make their own choices.
But more and more people are waiting for him to give the "correct answer."
And deep in the city, someone has already decided that human beings only need a correct evolutionary chain.
