Mysterious Agency

*In ancient times, there was an explosion on a planet not far away from ours, and the dark matter that it produced exterminated all living things on our planet. After a few thousand years, the first living being was born, it was the human. 
After that big explosion, a recessive gene appeared in the bodies of all the living creatures. We call it human-like, like an ancient man, like a ruthless man. This grass, like a flower, like a tree, is alive, so when the human-like genes in their bodies are multiplied and evolved, it will give them human characteristics. We call them mutants. 
He should have an ordinary life, Until one day he happened to see a murder case and involved into the other side of this world.  
How would he reveal the mysterious veil behind each case?  
Most importantly What should he do in the face of danger and betrayal …