Can you imagine that there is a train that cannot go to the future, but can only go back to the past? It's not time travel, it's observation. You can only look at it, but you can't touch it. Once you attempt to intervene, you will disappear into the cracks of time forever.
Chen Mo has the sharpest eyes on this train. He has no superpowers, he just relies on seeing people's hearts.
But when he tracked a ghost named "Old K" for half his life and finally blocked him at a certain historical scene, Old K turned around. That face he could see every day when he shaved.
"You're here." Old K said, "Now, help me kill myself in 1987."
Everything started to get out of control from this moment on.
It has that smell.