"A thousand-year-old man from the Tang Dynasty and a modern detective who doesn't believe in ghosts and gods have become each other's only antidote in a thousand-year conspiracy to hunt down immortals."
In modern cities, technology is highly developed, but there are always some "supernatural" cases that cannot be explained by science and are sealed in top-secret files.
His tacit partner who has traveled through thousands of years, he is his only confidant in his lonely years.
