Can you tell zombies will always be a fiction? Have you ever thought of a day you shall live a life out of security, praying for the worst will not fall down on yourself?

It was the question of all living creatures on Earth in the end of their 21th century.

They were real at last, the walking dead. When the first human infected by the Chronic Wasting Disease turned into a zombie, chaos soon rose within a decade. Deers had been wiped out in the efforts of stopping the spread, yet millions of people had been infected.

The only way to protect humans themselves was to build walls to seperate the infected and exclude them to the wild. It was the day humans could hardly live with mother nature again.

While humans had come to this surviving method, in Japan, a corporation named Paradise introduced a "have-never-seen-before" product, an AI that claimed itself to have gone to the Godhood. Machina was its name, and this AI was proposing humans to accept a program called "New Era of The World Tree".
It would bring humans to the World Tree it created, for them to live and experience a life of some real fantasy that they had never seen before.
And once more, humans found another mother nature to live with.

Paradise climbed to the top corporations of Japan, eventually the world within half a century, making them the most powerful corporation in AI technology and soon took over every single other company working in this field.

Was such a world come to real life really interesting?

Can you tell?