Shen Canglan, a descendant of tomb guardians, unearths a bone flute made from a hundred human skulls in an ancient tomb on Wushan. When the flute sounds, three thousand undead soldiers burst from the earth. He realizes they are the remnants of his souls from seven past lives. The flute is the Queen Mother of the West's "reincarnation calibrator": every time he plays it, he loses an emotion. Killing a blood relative unlocks his memories, but accelerates his transformation into a corpse.
The remnant soul of the Wushan goddess A Ruan appears, using a marriage pact and a curse to coerce him. She reveals that the undead soldiers are the beloved ones he sacrificed in each of his past lives, now his enemies. To break free of the karmic tribulations binding his seven lives, Shen Canglan takes a blood-rusted compass and a human-skin drum, and ventures into the Bronze Sacred Tree, the Yin Ruins, and the Queen Mother of the West's relics. As he loses his emotions and reckons with his sins, he finally burns the sacred tree with his soul flame, helps A Ruan find release, and discovers the truth of reincarnation.
