Episode 21 recap: He Yi Jing went to the north desert.

The master of the Linlang Pavilion told Mo Lin Lang and He Yi Jing that they had encountered the maid of the Crown Princess back then, and all the attendants had been buried with her. The Crown Princess, unwilling to part with her lover, faked her death and escaped to the north desert. Due to guilt in her heart, she didn't dare to reveal her identity to the prince, so she sent a letter explaining the truth of her supposed death.

When He Yi Jing opened the envelope and read the letter, he learned that the Crown Princess's death was related to the Emperor and the Empress Dowager, which greatly stirred his emotions. Mo Lin Lang saw how distressed He Yi Jing looked and quickly comforted him, saying that everything would be alright. Mo Lin Lang assured He Yi Jing that she would stand by his side no matter what.

He Yi Jing knew that the pavilion master was the seventeenth prince of the Jinba Kingdom and asked him for a favor. He Yi Jing took the initiative to request permission from his royal brother to go to the north desert and repel the enemies from the Jinba Kingdom. Mo Lin Lang sensed that something was off with He Yi Jing's emotions. He Yi Jing noticed that Mo Lin Lang had pricked her finger and became worried.

He Yi Jing realized that he had neglected Mo Lin Lang during the time he was busy with the war. He looked at the handkerchief that Mo Lin Lang had embroidered for him, although it was a bit rough, he felt it was the most beautiful handkerchief he had ever seen. Mo Lin Lang, after seeing He Yi Jing repeatedly apologizing for her own handiwork, started doubting her own skills.

He Yi Jing informed Mo Lin Lang that he would be leaving for the north desert the next day and expressed concern for her safety. Mo Lin Lang also expressed the desire to go to the battlefield. He Yi Jing felt that the north desert was a dangerous place, and he feared that Mo Lin Lang could get hurt.

Mo Lin Lang suggested that He Yi Jing use orpiment (yellow arsenic) as an explosive. Qian Jing Yi and the third prince planned to take advantage of the troops being led away by He Yi Jing and conspired to seize the throne.