After a fox spirit triggers the downfall of the Shang dynasty, a war sweeps across the three realms, destabilizing everything. The fox spirit is captured, and Jiang Ziya, a mortal who has risen to fame through the fighting, is assigned the grim duty of executing it. During the act, the fox spirit reveals there is a young girl inside her, and that proceeding with the execution would kill the girl as well. Jiang hesitates, but when the spirit fights to escape, his resolve hardens and he seems to finish the act. Convinced that the girl was merely an illusion conjured by the fox spirit, Jiang Ziya is stripped of his powers and banished to the North Sea until he can straighten out his mind and purpose.
Ten years pass, and Jiang lives a despondent life on a distant shore, accompanied by his friend Shen Gongbao and his loyal companion Si Bu Xiang. A chance encounter with Xiao Jiu, an amnesiac young fox spirit who resembles the girl he glimpsed, sets him on a new course. After a skirmish over a map, Jiang agrees to accompany Xiao Jiu toward Youdu Mountain, where she believes her father awaits, with Shen Gongbao in pursuit. Along the journey he faces a succession of dark threats—evil fox spirits and the tormented souls of the lost—testing his endurance and his changing heart.
At Youdu Mountain, Xiao Jiu meets King Zhou, who explains that she is bound to the original fox spirit and must be killed to truly defeat the former. Hearing this, Jiang attempts to kill Xiao Jiu, but his strike accidentally summons the fox spirit once more. Xiao Jiu clarifies that the girl was Su Daji, abandoned by her father to be offered as a concubine.
Together, Jiang Ziya and Shen Gongbao manage to confront the fox spirit, paying the price with the death of Si Bu Xiang. Shen Gongbao sacrifices some of his own power to spirit Jiang Ziya up to the heavens to seek guidance from the Master, Yuanshi Tianzun. The Master reveals that Jiang Ziya’s denial of godhood came not from a moral failure to kill the fox clan leader, but from a willingness to risk the fate of the world to save the girl. Jiang pleads for a chance to guide the girl to reincarnation, a plan that might kill the fox spirit once and for all.
To this end, Jiang takes Xiao Jiu to the Gate of Reincarnation, with Shen Gongbao keeping the fox spirit at bay. Yet the fox spirit breaches control, and as her power resurges, she confides that she was promised godhood but was instead used as a scapegoat to fight to unite the three realms. Jiang comes to see a painful truth: the so‑called Gate of Reincarnation is not merely a barrier but an abyss that locks away innocent souls from the wars. By helping the girl enter this abyss, he inadvertently leaves her trapped there. He makes a desperate effort to rescue her, breaking the lock she bears, while the Master dispatches a guillotine to end her life.
In that moment, Jiang realizes that his true power lies in self‑confidence and personal conviction rather than obedience to heaven. He appears to save the girl, but she is ultimately killed by the guillotine. The Heavens acknowledge Jiang’s act of destroying the fox spirit, and once again invite him to ascend to godhood. Yet the revelation of Heaven’s corruption leads him to reject that path, and he destroys the bridge between the human and heavenly realms, severing the two worlds’ hold over each other.
Years pass, and Shen Gongbao recounts Jiang Ziya’s story to a disciple, painting him as the supreme hero. In the end, a new life seems to begin: Xiao Jiu, reborn as a young girl, and Si Bu Xiang, reborn as a dog, play together—hinting at a new cycle of existence.
In a mid‑credits scene, three gods are shown standing guard over a heavenly prison, while another scene shows Jiang Ziya dining with Ne Zha and friends, reminding viewers of the intertwined fates of the immortals and mortals.
