In the underworld where undercurrents surge between the immortal and the underworld, Mu Yanxi, the nine-tailed fox son of the Mu family, lurks in the underworld as a "secret guard of the underworld". However, due to the "revenge" invitation from Xijun, the orphan of Yanran Mountain, he is involved in a blood contract conspiracy that spans three generations. Behind the seemingly idle case of family extermination, the immortal origin of the soul-burning nail, the forgery and tampering of the causal line, and the corpses in the secret passage of Yuelao Temple were exposed one after another. The two people suddenly discovered that since birth, their souls had been bound by an invisible red thread, and they had become living experimental subjects of the "Falcon Project" in the heaven.
When the nine-tailed fox fire meets the essence and blood of the unicorn, when the cynical disguise meets the obsession of the cold-faced avenger, they explore each other's bottom line in the black market puzzle, enter the fairy palace together on the night of the full moon, and look for the possibility of rewriting fate in the cracks in the line of cause and effect. And this cooperation that began with hatred will eventually turn into a sharp blade that pierces the hegemony of the three realms when the truth about the blood contract is revealed - even if the cost is to become the enemy of the entire world, the chain called "destiny" must be broken.
Intention: work together