Fang Tianxing comes from World A and is a forensic doctor. He is a very unlucky forensic doctor. He is so unlucky that every corpse that passes through his hands will twitch randomly.
Tianhei is from world B. He is a wolf, a wolf that looks a bit like a dog. He has a house and a car, and he knows how to use a gun. He likes to 'eat' people. To be precise, he just wants to eat Fang Tianxing now.