Years ago, the four prestigious sects join hands to try and defeat Wen Ruohan. When Nie Mingjue goes up to attack Wen Ruohan one-to-one, he gets overpowered and Lan Xichen begins to help out. But even with the combined effort, Wen Ruohan's powers are impenetrable. Finally, Jin Guangyao ambushes him from behind, stabbing him to death and ending the Sunshot Campaign. In the present, Lan Xichen goes to the Carp Tower to visit Jin Guangyao. In the Cloud Recesses, Wei Wuxian tries to run away but Little Apple refuses. He remembers the need for the passage token to leave the Cloud Recesses's barrier and decides to sneak into the Cold Spring and steal one. He finds someone bathing in the spring and sees their back covered in scars from a discipline whip (which can never be removed). He uses a spell to take the token from the clothing but the bather, Lan Wangji, catches him red-handed.

Lan Wangji and Wei Wuxian continues their search and arrives in a forest. At the same time, Jin Ling is also here to night-hunt but meets Sect Leader Yao. The latter starts attacking him and this catches the attention of Lan Wangji and Wei Wuxian. The two then rush to stop Sect Leader Yao. Wei Wuxian explains the large amount of resentful energy here is causing hallucinations and Jin Ling is unaffected because of the Yunmeng bell. Later, the three of them discover the guards of the observation tower killed by a mysterious beast. As the air grows ominous, a snake-like beast attacks them. With the efforts of the three, they successfully kill the monster. However, as Sect Leader Yao talks about Jiang Yanli and Wei Wuxian, Jin Ling runs away. He ends up in a place full of corpses and Lan Wangji and Wei Wuxian hurry over. A head attacks them and Wei Wuxian represses it. With Lan Wangji's guqin, they find out the head belongs to the deceased Jin Zixun, an uncle of Jin Ling. The memory of his death at Wei WuXian's hands after he tried to force him to remove a curse he supposedly placed on him unveils. The effects of the curse on Jin Zixu's body should remain even after death, unless the caster had died. His body disappeared after Wei WuXian's death, so no one could confirm the marks had dissipated, which they would have if Wei WuXian cursed him - possibly to conceal the fact the marks remained even after the death of the Yiling Patriarch.

Jiang Cheng arrives and fights Wen Ning but the latter manages to escape. Jiang Cheng then confronts Lan Wangji and Wei Wuxian as he still doubts this "Mo Xuanyu". He ultimately leaves with Jin Ling. Before they leave, Wei WuXian destroys the zombie array at the mountain so it will stop collecting resentful energy and trapping people, something Lan Wangji, despite his cultivation level, is unable to do. Nothing further is found on the mountain so they leave to continue investigating. They meet the crazy woman again and find a pile of dead bodies with sword marks from Shuanghua. Lan Wangji explains the sword belongs to a talented cultivator named Xiao Xingchen. The arm goes out of control again and escapes from the Cloud Recesses. After this news reaches Lan Wangji and Wei Wuxian, they uses the Compass of Evil — linked with the head from earlier — to find the arm; and the two go to Qinghe. Jiang Cheng also sets off to the same place. In Qinghe, Wei Wuxian bumps into a merchant selling portraits of the Yiling Patriarch. While Wei Wuxian argues with him about how ugly he is drawn, Jin Ling comes and kicks the merchant, stating that he hates anyone who mentions Wei Wuxian's name. Wei Wuxian and Jin Ling quarrels a little and Jin Ling calls his dog Fairy over. Scared, Wei Wuxian runs back to Lan Wangji. Jin Ling walks away with Fairy and the two goes to Xinglu Ridge. On the way, Wei Wuxian hears the dog barking again and Lan Wangji asks why he is scared of dog, leading Wei Wuxian to remember the time he gets taken in by Jiang Fengmian.

Wei Wuxian and Lan Wangji follow the sounds of Fairy barking and are led to a tower. Seeing that a hole is blown on the wall, they enter to start finding Jin Ling. On the other hand, Jin Guangyao and Lan Xichen are trying to find Nie Huaisang. Upon entering the tower, Lan Wangji and Wei Wuxian find a coffin with a sword inside. Lan Wangji then plays Inquiry to ask for Jin Ling's whereabouts. With the replies from the spirit, they find Jin Ling unconscious inside the wall. The tower then starts to crumble and attack. They immediately bring Jin Ling outside. Fairy suddenly senses something and runs off. Lan Wangji tells Wei Wuxian that he will chase after it and will meet up again later. Wei Wuxian then looks at the cursed marks on Jin Ling's leg and wonders what hallucinations he is having from it. He then transfers the marks onto himself, making him hallucinate too. A young Jin Ling gets bullied by other children and Yiling Patriarch Wei Wuxian approaches him. He introduces himself as his uncle from the same discipline. When Jin Ling asks him about his parents Jin Zixuan and Jiang Yanli, Wei Wuxian recalls the times he spent with the two.

Jin Ling wakes up in the inn and vaguely recalls last night's events. On the other hand, Jiang Cheng and Wei Wuxian argue about the latter's misdeeds. However, Wen Ning suddenly appears to protect Wei Wuxian and the three fight outside. Wei Wuxian chases Wen Ning away to prevent him from losing control and runs away too. He gets chased by Fairy and enters an abandoned residence to hide from it. Jin Ling shows up and the two talk for a bit. When he says that Jiang Cheng hates Wei Wuxian to the bones, Wei Wuxian reminiscences about his childhood with Jiang Cheng and Jiang Yanli. He also apologises to Jin Ling about his actions on Mt. Dafan before Jin Ling leaves. Wen Ning returns to meet Wei Wuxian and the latter starts to remember the time when he protected the Wen sect remnants from everyone else and how he was constantly forced to hand over the Stygian Tiger Seal. Wei WuXian also looks into Wen Ning's memories and discovers that the Jin Sect and Lan Sect had worked together during the past years.

Jin Guangyao and Lan Xichen discuss about the connection between the mysterious hand and Ghost General. Back in the abandoned residence, Wei Wuxian regains Wen Ning's consciousness and asks about what happened. However, Wen Ning cannot remember much about his days of being locked up, except the presence of Jin Guangshan and two other people. Wei Wuxian then faints from the effects of the cursed marks and remembers his time in Yiling 15 years ago. Wei Wuxian finds Wen Yuan with Lan Wangji and decides to enjoy a meal with the latter. Although Lan Wangji tries to warn him of the consequences of demonic cultivation, Wei Wuxian reassures that he will not be harmed. Suddenly, trouble arises in the Burial Mound and they rush back to find Wen Ning going berserk. They work together to suppress Wen Ning and successfully regain his consciousness. Wei Wuxian then sends Lan Wangji off and the two share another conversation about Wei Wuxian's decisions. The latter is unwilling to give up on the Wen Remnants but is determined not to lose control, and hence the two part ways. One year later, Jin Zixun ambushes Wei Wuxian and Wen Ning on Qiongqi Way while they are on their way to Jin Ling's one-month anniversary.

Wei Wuxian faints after the incident at Qiongqi Way and wakes up in his cave in the Burial Mound. When he sees Wen Ning, he beats him up in rage and cries about not knowing what to do. Wen Qing then uses a needle to render him weak and explains that she and Wen Ning will confess their crimes. Even though Wei Wuxian refuses, he is unable to stop them and only wakes up 3 days after. He goes to the Nightless City where the other sects are holding a ceremony to pay their respects to those who had fallen, and to also kill Wei Wuxian and the Wen remnants. Wei Wuxian wants to find out the truth behind the Hundred Holes and a fight ensues. Lan Wangji tries to reason with Wei Wuxian but he is too far gone to listen. Suddenly, Jiang Yanli arrives on the battlefield to find him but gets injured by a fierce corpse. While Wei Wuxian holds her dearly in his arms, Jiang Yanli tells him to stop. The latter did, but Jiang Yanli pushes him away from an incoming attack and suffers the stab in his place. Wei Wuxian goes berserk again and unleashes the power of the Stygian Tiger Seal. Wei Wuxian wakes up from the flashbacks to find himself under Lan Wangji's care. The cursed marks are suppressed and Lan Wangji returns him his Yunmeng bell and temporary flute. Wei Wuxian then enjoys a meal with him to regain his strength. At the table, they then discuss about Wei Wuxian's dream and Lan Wangji suspects that someone else has been behind the deaths in the past. Suddenly, the window opens.

Nie Huaisang enters the room to plead them for him to leave, but Wei Wuxian begins to interrogate him about the tower. On the way there, Nie Huaisang explains that the human-eating tower is in fact just a fabricated rumour to discourage people to enter, and the ruckus are all caused by the swords left behind by the deceased Nie Sect ancestors. When they arrived, they find corpses and a group of black-clad people preparing to attack them. Wei Wuxian engages them while Lan Wangji goes to check the tower. When Nie Huaisang is suddenly targeted, Lan Xichen and Jin Guangshan arrives to aid them. During the fight, Lan Wangji and Wei Wuxian discover that one of the black-clads is skilled in Gusu's sword techniques and has the Hundred Holes. The zombie hand also appears and Wei Wuxian questions the link with it. After, they find a pair of legs that matches with the zombie arm, sewn into one of the corpses. They then part ways and Wei Wuxian and Lan Wangji continues their search for the other parts. The zombie hand points them to a new direction and the two set off West. In town, Lan Wangji tries to ask how Wei Wuxian has died, but the latter refuses to tell. He then finds a pellet drum for sale and remembers how he used to love this toy. In the post-credit scene, Jin Guangyao is up to something in his treasure room and Lan Wangji and Wei Wuxian arrives in Yi City, meeting Xiao Xingchen.