C430 Level One Alert

Zhuang Chen squatted in the corner, his chest heaving up and down.

His breathing became rapid and disorderly. He put his ears on the wall to listen to the noise outside.

"Buzz..."

"Not good, there is a large number of zombies approaching us. Be on guard immediately."

"Level one alert."

"..."

A long and piercing warning sound rang out in the sky