The heavy snow has not stopped for several days, and Di Renjie has been in a coma since he came out of the underground palace. Cao An suspected that Di Renjie was influenced by the altar and proposed to leave the library overnight. Li Miao arranged for his disciples to carry Di Renjie into the carriage, while Cao An drove alone. Di Renjie saw Cao An leaving in his dream. When he woke up, he saw Ma Rong and Qiao Tai, but Cao An was not there. There was only a note saying: "The axle has been broken, I will go look for him."
Di Renjie felt something was wrong and suspected that Cao An was in danger. Sure enough, the crazy grandma in the inn recognized the wooden sword that Cao An had picked up, and became extremely excited. She shouted her grandson's name "Wei Xiaobao", which attracted Di Renjie's attention. Cao An once saw records about child sacrifice in a sheepskin book. Di Renjie looked up and noticed a strange phenomenon in the sky, and immediately returned to Chaoyun Library with Ma Rong and Qiao Tai.
The library was extremely quiet at this moment. The three of them were hiding in the corner of the main hall and witnessed a group of disciples wearing black robes entering the underground palace, followed by Di Renjie. Disciple Lin Shu stood directly in front, leading everyone to bow their heads in prayer, chanting obscure incantations, and his eyes were full of evil and greed, which was very different from usual.
Di Renjie then used his memory to find the underground palace cell and found the missing boy Wei Xiaobao. Just as he was slashing the chains with his sword, Li Miao came out from the side and admitted that he had killed Cui Haoran and imprisoned Cao An. But before Di Renjie could get closer, he waved his hand and scattered the smoke before snatching away Wei Xiaobao and disappearing without a trace. Only his voice could be heard.
Ma Rong and Qiao Tai fought all the way into the underground palace. They did not see Cao An when they arrived, but they found the old man's body in the tung oil jar in the study. At this time, another group of disciples came to block the way. Ma Rong and Qiao Tai were responsible for cutting off the rear, while Di Renjie rushed to the real altar and interrupted Li Miao's sacrificial ceremony.
Li Miao became angry because of this and refused to tell where Cao An was. Di Renjie's inquiries were fruitless, and Li Miao committed suicide by taking poison. Before he died, he laughed at Di Renjie, even if he found Cao An, it would only be her corpse. Di Renjie realized that Cao An was dying and was extremely anxious, but he tried to keep calm. He deduced the location through memories and finally found Cao An in a hole in the wall.
Fortunately, Ma Rong and Qiao Tai arrived in time, and the three of them worked together to cut through the wall and rescue Cao An. Cao An, who was originally unconscious, gradually regained consciousness. In Cao An's narration, the mystery of the case was finally clarified. In fact, Cao An vaguely knew the answer from the moment he picked up the small wooden sword. Later, he found Wei Xiaobao in the corner and found out why Zhou Li died.
A year ago, Li Miao killed Cui Haoran, occupied the magpie's nest, and continued to recruit disciples in the name of the academy. In Li Miao's eyes, these disciples are all sacrifices, and they will kill people every bad day in the vain hope of immortality. Because the disciples have been brainwashed by Li Miao, they don't think there is anything wrong with killing a child. But Zhou Li still had a conscience and secretly let Wei Xiaobao go and took him to Cui Haoran's room, which happened to be the night Di Renjie was going to visit.
In order to protect Wei Xiaobao, Zhou Li carried him back from the outside to the door of the room, leaving deep footprints. Finally, he used a snowball to smash the door to lure Cao An away. Wei Xiaobao took this opportunity to sneak into the house. Zhou Li originally wanted to die to reveal the truth, but unfortunately the clues were hidden by Li Miao, so Wei Xiaobao had no choice but to throw sandalwood at the door to attract attention.
Cao An felt that Li Miao was suspicious of him, so he had to pretend to cater to him, pretending to be afraid of the undead, and found an excuse to drive away in a carriage overnight, and agreed to meet Wei Xiaobao at the foot of the mountain. Unexpectedly, Li Miao had already seen through the plot, and not only captured Wei Xiaobao, but also tied her into a hole in the wall and plastered the wall with mud.
As time passes, the air thins, and death approaches. Cao An is not afraid of death, his only concern is that Di Renjie will be safe. Di Renjie was deeply moved after listening to Cao An's words, and carried her out of the underground palace. Wei Xiaobao recognized his grandma and gave Di Renjie a wooden sword as a gift to express his gratitude. After this incident, Di Renjie completely let go of his worries and personally put on the earrings for Cao An. The two hugged each other tightly and cherished this moment for the rest of their lives.