Episode 21 recap: Zhou Shi Yu persuaded the Prince of Zhen Nan.

The Empress Consort Su Su found Yue Ling, as they had a past relationship, and still wanted to persuade her to leave the Prince of the North. In the past, when Yue Ling was confined in the Cold Palace, it was Su Su who secretly unlocked the door, as her position was too low to show herself, but this was all at the secret request of the Prince of the North. The Prince of the North came from far away and wrote a letter in autumn, first to resolve the princess' predicament, second to express his determination to marry the princess, and third for the peace of the realm.

Yue Ling also knows that the Prince of the North has made many sacrifices, and she will definitely appreciate him in the future. Su Su persuaded Yue Ling to leave the Prince of the North, as the Prince of the North has risked his life twice when going to East Yu, and Yue Ling knows the reason why. Although the marriage alliance has dealt a heavy blow to the faction of the Prime Minister, the Prime Minister's ambition is blatant and he will not easily give up. At that time, the Emperor and the Prince of the North will find it difficult to cope, so the Prince of Zhen Nan has become the key.

Yue Ling knows that the Prince of Zhen Nan is the brother of Gao Luo Yi, and then learns that the Prince of Zhen Nan has demanded that Gao Luo Yi marry the Prince of the North. The subordinates of the Prime Minister interrogated Ling Xi about Su Nian's whereabouts, and Ling Xi knew that Su Nian did not have the antidote, so she did not keep an eye on her. The subordinates demanded that Ling Xi must find Su Nian, alive or dead.

Yue Ling was lost in thought while holding a book, and she didn't even notice when Zhou Shi Yu came in. Yue Ling asked Zhou Shi Yu the reason for his long absence, and inquired about their marriage engagement. Zhou Shi Yu concealed the matter of the imperial betrothal, and casually talked about other things. Yue Ling did not continue to ask, and asked about the situation of the Prince of Zhen Nan. Zhou Shi Yu also considered the Prince of Zhen Nan to be very important, as he has a large army, but has not yet decided which side to support. Zhou Shi Yu felt that Yue Ling had already heard others mention the Prince of Zhen Nan, and Yue Ling understood that Zhou Shi Yu did not want to talk about it and supported him.

Yue Ling was distressed in her heart, and went to talk with the Duke of Quan. The Duke suggested that they immediately get married as a first step. Yue Ling was worried that the time was too rushed, but still immediately issued an order to recruit suitors throughout the city. At night, Yue Ling was still worried, and Qian Qian knew that she still could not let go of the Prince of the North. Yue Ling felt that she must take some action, otherwise it would make things even more difficult for Zhou Shi Yu.

Zhou Shi Yu took the initiative to find the Prince of Zhen Nan, hoping that the Prince would not go to great lengths to have the imperial betrothal merely spread to Yue Ling's ears. The Prince of Zhen Nan was furious at Zhou Shi Yu's attitude, and Zhou Shi Yu then proposed that the Prince of Zhen Nan stay in the capital, hoping to gain the Prince's support.

Yue Ling was lost in thought while holding a book, not even noticing when Zhou Shi Yu entered the room. Yue Ling asked Zhou Shi Yu why he had been away for so long and about their marriage arrangement. Zhou Shi Yu concealed the news of the imperial decree and casually changed the subject. Yue Ling did not pursue the matter further, and instead inquired about the Duke of Nanzhou's situation. Zhou Shi Yu also considered the Duke of Nanzhou to be very important, as he commanded a large army, but had not yet decided which side to support. Zhou Shi Yu felt that Yue Ling had already heard about the Duke of Nanzhou from others, and Yue Ling understood him and supported his decision.

Troubled in her heart, Yue Ling sought out the Marquis of Shiquan to confide in him. The Marquis suggested hastening their own marriage as a solution. Yue Ling was concerned about the rushed timeline, but still immediately issued a decree to summon suitors throughout the city. That night, Yue Ling was still worried, and Qian Qian knew that she still could not let go of the Northern Prince. Yue Ling felt she must take some action, or else she would put Zhou Shi Yu in an even more difficult position.

Zhou Shi Yu proactively approached the Duke of Nanzhou, hoping the Duke would not go to great lengths to spread the news of the imperial decree to Yue Ling. The Duke was angered by Zhou Shi Yu's attitude, so Zhou Shi Yu proposed that the Duke remain in the capital, hoping to gain his support.

When the Southern Prince learned that Princess Yue Ling was openly seeking a suitor, he immediately recognized the opportunity and decided to go to the palace. At the same time, Gao Luo Yi also knew of Yue Ling's public suitor recruitment, believing his chances with the Northern Prince were close at hand. However, Yue Ling tactfully withdrew.

After waiting for a morning, no one had arrived, and Yue Ling was puzzled when the Southern Prince suddenly entered. Yue Ling had wanted to find a talented young man, and felt deeply disappointed upon seeing the Southern Prince. Outside, Yang Xu had prepared a large sum of silver to thank all the young men for participating, but the Princess had already found her match.

Yue Ling asked the Marquis of Shiquan to assess the Southern Prince. The first test was a literary examination, which the Southern Prince surprisingly excelled at. In the second martial arts test, the Southern Prince took advantage of his opponent's physique and attempted to gouge his eyes. At this point, the Northern Prince arrived and requested to participate in the trials as well. Since this was an open suitor recruitment, Yue Ling could not intervene.

In the final test, Princess Yue Ling personally examined the candidates. The first question was about the most beautiful place, and the Southern Prince cited the mountains and rivers of the north, while Yue Ling should long for the vast grasslands of the east. But the Northern Prince believed the most beautiful place was the small river bank where they had first met. The second and third questions about the most precious dessert and the most treasured possession were also answered correctly by the Northern Prince.

The Southern Prince won two rounds, while the Northern Prince won one. As the two sides debated, a decree was issued from the palace, announcing the engagement of Yue Ling and Zhou Shi Yu.