Episode 21 recap: Jiuling set fire to the astrology pavilion and the star map. The Regent Prince wanted to get rid of Jiuling.

Jiuling went to meet the Emperor to discuss how to destroy the star map. She had already come up with an idea: she planned to set fire to the astrology pavilion. However, there were many sorcerers in the pavilion, and Jiuling was worried about harming innocent people. She asked the Emperor to find a way to relocate those sorcerers. The Emperor then had an idea. He suggested using the Empress Dowager's birthday banquet as an opportunity to invite all the sorcerers to the palace to congratulate her.

The princess arrived at the Rong residence in a fuss, demanding to see Rong Yu. Zhan Ping couldn't stop her, so Rong Yu had to come out and persuade Zhan Ping to return to the house with him. The princess told Rong Yu that she couldn't play the qin well, so she wouldn't attend the Empress Dowager's birthday banquet and suggested that Rong Yu go alone.

Rong Yu ignored her, which made the princess angry. She swung a whip at him, narrowly missing Rong Yu. Jiuling arrived just in time and grabbed the whip, causing the princess to stumble. Jiuling angrily stated that the whip was her plaything and asked if the princess dared to overstep her boundaries with Rong Yu. The furious princess retorted that she wouldn't perform alongside someone as mentally deranged as Rong Yu.

After the princess left, Zhan Ping was worried. How would Rong Yu handle the situation alone? Jiuling said that since they had agreed to do it, they would go. She asked Rong Yu to play the qin for her again. The time for the Empress Dowager's birthday banquet arrived, and the Empress Dowager called for the princess, instructing her not to provoke Jiuling and Rong Yu. The princess, surprised by the Empress Dowager's favor towards Jiuling, reluctantly agreed.

Rong Yu and Jiuling prepared to attend the banquet. Jiuling decided that she wouldn't act as the Junior Mistress of the Astrology Pavilion tonight. Instead, she wanted to be a dancer. Rong Yu handed her a farewell letter and told her to do what she wanted. Reluctantly parting ways, they arrived at the banquet. Rong Yu played the qin, and Jiuling performed a graceful sword dance, winning the admiration of everyone present.

However, because Jiuling wore a mask, everyone mistook her for the princess and believed that Rong Yu and the princess were a perfect match. Only the princess realized that everyone had collectively forgotten that Rong Yu had a legitimate wife. Jiuling returned in a carriage, instructing her subordinates to start the fire, and then she secretly infiltrated the secret chamber under the pretense of rescuing people from the fire.

Rong Yu rushed back as quickly as possible, but Jiuling had already set fire to the star map in the secret chamber. When she emerged, she was overcome by smoke and fainted on the ground. The old sorcerers wept bitterly, realizing that from that point on, the fate of the country and even the future of the auspicious unicorn were no longer under their control.

Rong Yu saw Cheng Bi desperately trying to rush into the secret chamber and knew something was amiss. Ignoring the danger, he dashed inside and indeed found Jiuling lying there. He endured the smoke and carried Jiuling out. Rong Jiang hurried back and saw the devastation caused by the fire, feeling utterly hopeless. At that moment, Rong Yu emerged, carrying Jiuling, and everyone rushed forward to receive them. Rong Jiang saw the star map destroyed and Rong Yu collapsed on the ground, coughing up a mouthful of blood.

Rong Yu remained unconscious, and when Jiuling woke up, she learned that Rong Yu had been seriously injured while saving her and hadn't regained consciousness. She became extremely worried. Rong Jiang heard from his subordinates about the cause of the fire and realized that he had invited trouble into his own home. He reported the incident to the authorities and had He Jiuling arrested. When the Emperor found out, he was furious.

The Regent Prince came to find Rong Jiang, wanting him to perform another divination, but Rong Jiang had no interest in divination. He looked at Rong Yu lying on the bed and believed that he didn't want to wake up. Rong Jiang talked to the Regent Prince about Jiuling setting fire to the astrology pavilion. The Regent Prince asked why Jiuling would do such a thing. Rong Jiang replied that Jiuling probably found out that he was responsible for the annihilation of the He family. He had noticed Jiuling's abnormal behavior earlier, and he wanted to make sure Jiuling had no place to die, to completely destroy her.

The Regent Prince said that He Jiuling was now helpless and killing her would be as easy as turning his hand. He decided to send someone to eliminate Jiuling and vent his anger for Rong Jiang. That night, the Regent Prince's men arrived at the dungeon. They first silenced Jiuling, then escorted her out of the prison. Rong Yu had already woken up, and he overheard the conversation between Rong Jiang and the Regent Prince. After Rong Jiang left, Rong Yu opened his eyes. He had already divined that Jiuling would soon be killed by an assassin, so he urgently instructed Zhan Ping, who was serving by his side, to help him leave.