Zhang Zhen, a scholar, was engaged to the Prime Minister's daughter, Peony, but when his parents died, he defected to the Prime Minister's residence. Seeing that he has no money and no power, the prime minister orders him to study in a hut by the Bibo Lake in the back garden, but he wants to find a chance to repent his marriage.

Zhang Zhen was in a bitter mood, and often went to the pool alone to sigh his heart, and the carp spirit in the pool adored Zhang Zhen's goodness and simplicity, so he turned into a peony and met with him in the study, and the two of them were in love with each other.

One day, Zhang Zhen met the real peony and called the peony "mother". The prime minister rebuked him and drove him out of the palace. The carp went out of the palace to chase after him, and the prime minister saw them, mistaking his daughter to be running away with Zhang Zhen, so he arrested them back to his palace.

The two peonies are hard to distinguish between the real and the fake, and the prime minister invites Bao Gong to make a judgment, and the carp spirit invites the turtle spirit to change into Bao Gong, who also appears in the minister's residence. Under the skillful hints of the fake Baogong, the real Baogong learns the truth, and in order to fulfill the two people, he excuses himself from asking questions, and the two people take advantage of the opportunity to escape.

But the Prime Minister refused to give up, and asked Zhang Tianshi to bring in heavenly soldiers and generals to catch up with them. The carp spirit told Zhang Zhen about his life, and Zhang Zhen did not think it was strange, but valued this true love even more.

At the critical moment, Guanyin appeared, willing to cultivate the carp essence to become immortal, but the carp essence does not want to become immortal, turned into a mortal and Zhang Zhen married.