On the surface, the Dasheng Dynasty is ruled by the imperial court, but secretly it shares the world with the sects on the mountain. Mortals respect and fear immortals, but they don't know that many immortal sects have already regarded the world as a chessboard for power and profit. The protagonist was brought up by a reclusive swordsman since he was a child. He went down the mountain to deliver a message for the first time, but during a chase, he mistakenly used the ancient sword left by his master as a fire stick, accidentally activating the secret that had been sealed for many years in the sword. That sword is not an ordinary magical weapon, but a bone sword that can "cut off the false and preserve the true." Any aura, identity, or oath illuminated by it may reveal its true form. The imperial court, immortal sect, orphans from old cases, and defected disciples are all involved in the fight. Only then does the protagonist realize that what he has sent down the mountain is not a letter at all, but a lead that can overturn the order of the two worlds.
