"Does a fairy have a tail?"
This sentence is a guess based on the established fact that fairies exist. Then he overturned his guess.
"After all, do fairies exist?"
Since it is not known whether fairies exist or not, it is even less clear whether fairies have tails.
"So it's a perpetual mystery and a perpetual adventure."
This is the story of Luo Ling becoming an angel due to an accident and going on an eternal adventure in the infinite world.
This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.