Episode 20 recap: Gu Xing He's father is pressuring Gu Xing He.

Bao Rou Rou wonders why everyone desires immortality. If that weren't the case, her father wouldn't have left her, and she wouldn't have to worry about Gu Xing He leaving one day. Gu Xing He assures her that even if he disappears, his love for Bao Rou Rou will never fade.Gu Xing He pleads with his father to keep the secret. Gu Xing He's father promises to keep it, but once the task is accomplished, Gu Xing He must sever ties with Bao Rou Rou. Gu Xing He reluctantly agrees. Bao Rou Rou insists on weaving the Mermaid Silk and, upon returning, Gu Xing He gives her the loom. Bao Rou Rou weaves for a long time but still fails to produce the fabric.

Bao Rou Rou wonders why everyone desires immortality. If that weren't the case, her father wouldn't have left her, and she wouldn't have to worry about Gu Xing He leaving one day. Gu Xing He reassures her that even if he disappears, his love for Bao Rou Rou will never fade.

The loom was left by Gu Xing He's mother, and his father is astonished when he realizes it's gone. Gu Xing He's father now knows that Bao Rou Rou is a mermaid and blames Gu Xing He for neglecting his duty to the emperor and his family.

Gu Xing He reveals that the Crown Prince and Feng Xuanzi are colluding. Gu Xing He's father admits that he supported the Third Prince to become the Crown Prince in the past and is not opposed to supporting the current Crown Prince as long as the Gu family is protected. Gu Xing He pleads with his father to keep the secret. Gu Xing He's father promises to do so but insists that once it's over, Gu Xing He must sever ties with Bao Rou Rou.

Gu Xing He reluctantly agrees. Gu Xing He's father demands that Gu Xing He make an oath using his mother's name, and Gu Xing He has no choice but to comply. Bao Rou Rou finally weaves the Mermaid Silk successfully and is overjoyed. Bao Rou Rou and Gu Xing He go to Feng Xuanzi's place, where he purposely wets Bao Rou Rou's leg, but she remains unharmed, surprising Feng Xuanzi.