When the Nie family of Qinghe faces a crisis, Mingjue and his younger brother Huaisang join hands to surpass every obstacle. However, the brothers are constantly at odds with Mingjue accusing Huaisang of being cowardly, and Huaisang of complaining Mingjue arrogant and cruel. Despite the conflicts, they always help each other in times of danger. The brothers eventually lead the people to end the crisis and defend the peace.
Two grave robbers break into Sword Sacrificing Hall, the Niè Clan Ancestral Tomb, in the hopes of finding treasure. Instead, they discover that all of the coffins have blades instead of bodies inside them. Whilst one starts collecting the decorative jewels from the sides of the coffins, the other is compelled to wander to a wall and light a stick of dynamite. The second follows the noise and discovers an arm with jewelry which he proceeds to rob before blood falls on his face from the ceiling. He looks up to see the ceiling moving and tries to flee but is dragged back by an unseen force.
Niè Clan Leader Niè Mingjue receives news of the disturbance at Sword Sacrificing Hall and orders one of his disciples to fetch his younger half-brother Niè Huaisang who he orders to accompany him on the mission. When Niè Huaisang tries to evade going, Niè Mingjue publicly criticizes his brother for refusing to cultivate with a blade and spending his time painting breaking his brush in his anger. He almost attacks Niè Huaisang in a qi induced rage but Jin GuangYao calms him with the Song of Clarity just in time.
Niè Huaisang later rants to Jin GuangYao about how Niè Mingjue is dying from qi deviation but still wants his brother to take up the blade and follow in his footsteps. Jin GuangYao gifts Niè Huaisang with a wooden flute and offers to teach him a passage from the Song of Clarity to help his brother.
The Niè disciples ride out to Sword Sacrificing Hall only to be attacked outside by man-winding vines. Three disciples are killed. Niè Mingjue and two other disciples are separated from the main group where the man-winding vines ensnare them. Niè Mingjue breaks free in his fury and Niè Huaisang tries to play the Song of Clarity so his brother can find them again.
Niè Mingjue sees two puppets like the ones created by the Wen Clan and kills them before returning to the main group. The group escapes the man-winding vines inside Sword Sacrificing Hall where they realize the Sword Spirit has been greatly disturbed due to the rage the vines are exhibiting.
Niè Mingjue puts himself and Niè Huaisang in charge of two teams for two separate rooms to repair one of the Hall's Matrixes. Niè Huaisang proves his knowledge of astronomy to place all the coffins back where they should be. Niè Zhongui explains to Niè Huaisang that the walls of Sword Sacrificing Hall are filled with corpses to prevent the Sword Spirit from breaking free and destroying Qishan. Horrified, Niè Huaisang delays going out of the tomb resulting in one of the disciples being crushed trying to hold it open.
Meanwhile, Niè Mingjue's group is attacked by man-winding vines and creates a formation to keep them away. They are trapped until the formation is destroyed. One of the disciples is dragged into the wall and smothered to death.
With the Matrix fixed, the groups meet in the main entryway to head into the main part of the tomb. Niè Huaisang confronts his brother about the use of corpses essentially sacrificing people's souls to control the Sword Spirit, he questions whether the Niè clan has the right to decide if they were evil people and that they are still human. Niè Mingjue snaps at him and Niè Huaisang questions his brother's state of mind as a result of his qi starting to deviate. Niè Mingjue briefly hallucinates that two of the disciples are puppets.
Niè Mingjue orders the disciples onwards where they come to a bridge over a wide gorge. Still angered about his brother's stubbornness, Niè Huaisang storms over the bridge first but almost falls through when some of the planks give way. The group is attacked by bats that cause one disciple to fall off the bridge which they then destroy before Niè Huaisang can get to the other side. Niè Mingjue dives after his brother using Baxia to hold them in place on the gorge wall.
Niè Huaisang apologizes to Niè Mingjue who sends him back to the pathway with Baxia using his spiritual energy before falling into the gorge.
A flashback to their childhood shows how Niè Mingjue gifted Niè Huaisang with his paintbrush and promised his younger half-brother that no matter what he chose he would always protect him. Stricken with guilt, Niè Huaisang ties a rope to his waist and dives into the gorge but it breaks and he is trapped at the bottom. He ends up trapped going round in circles and hears voices blaming him for failing the Niè Clan.
Niè Huaisang passes out and wakes in a room with Niè Mingjue. Niè Mingjue apologizes to him and admits his qi is deviating beyond his control and he will likely die very soon. The room they are in is where previous Niè Clansmen used to chain themselves before they lost control. Niè Huaisang hears running water and uses the carvings on the walls to find a stone formation on the floor that the brothers use to get out.
They meet up with the rest of the disciples and Niè Mingjue resolves to finally destroy the Sword Spirit. Despite their best efforts, the Sword Spirit proves too strong knocking out the disciples including Niè Huaisang, and possessing Niè Zhonghui. Niè Minhjue loses control of his qi and destroys the Sword Spirit and Niè Huaisang tries to play the Song of Clarity to calm him. However, his brother instead loses control killing Niè Zhonghui and two other disciples in a blind rage.
He almost kills Niè Huaisang but snaps out of it at the last second. When he asks what happened, Niè Huaisang lies and says the Sword Spirit killed the disciples and Niè Mingjue breaks down crying.
The brothers bow to the statue of the Niè Ancestor and depart home.
The film states that Niè Mingjue died of Qi Deviation at Carp Tower and shows his funeral at Qishan. Niè Huaisang is grieving his brother's death when the wind blows a book open to a page on music. Niè Huaisang realizes that the Song of Clarity Jin GuangYao taught him had a wrong passage that caused Niè Mingjue to react violently.
Just then Jin GuangYao enters and tells him to calm his grief. Niè Huaisang thanks Jin GuangYao and bows to him hiding his face as he glares at the man who murdered his brother.