What Exactly Is the Mysterious Resurgence?

"Do those things really exist in the world? I don't know, but let's run! Don't take what you see in front of you as real, the most important thing is to live!"... This came from a worn-out tape, and the words were very confusing. You can tell from the heavy breathing that he is running. There must be something chasing him behind him! Then what does he mean by this sentence? ! ! This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.