Every evening the Fisherman goes out to sea and throws his nets into the water. One evening, he accidentally catches a sleeping Mermaid, and refuses to let her go unless she promises to return whenever he calls so that she can sing for him and help him catch fish. The Mermaid agrees, and every evening she returns to sing. Soon the Fisherman falls in love with the Mermaid and asks her to marry him. The Mermaid, however, replies that she can only be with him if he sends away his soul, as the Sea-folk are soulless.
The Fisherman seeks guidance on how to rid himself of his soul from the Priest, who is appalled and tells him the “love of the body is vile,” adamantly refusing to help him. The Fisherman then goes to the Witch, who is similarly aghast at the idea. Nonetheless, after attempting to make the Fisherman take part in a strange Satanic ritual, she reluctantly tells him how to cut away his shadow, which is in fact the body of his soul.
As the Fisherman makes his way to the shore to perform the spell the Witch has described, his Soul begins to call out to him, begging not to be sent away. When it becomes clear that the Fisherman is determined to be with the Mermaid at whatever cost, the Soul then begs not to be sent out into the world without a heart. The Fisherman also denies him this. The Soul, however, says they must meet again, and that he will return to the same place every year.
After the first year is over, the Soul returns and calls the Fisherman up out of the sea. The Soul describes at length his journeys to the East where he obtained the Mirror of Wisdom, telling the Fisherman how he then hid in a valley “but a day’s journey from this place” and suggesting that the Fisherman come and take the mirror so that he “shalt be wiser than all the wise men.” The Fisherman, however, is unmoved, simply saying, “Love is better than Wisdom.”
After the second year, the Soul again returns and recounts his travels, this time to the South where he obtained the Ring of Riches which he has also hidden in the valley. Again, he says the Fisherman should come and take the ring so that “the world’s riches shall be thine.” Once more the Fisherman is not to be tempted, replying, “Love is better than Riches.” After the third year when the Soul returns, he describes an inn in a city where a veiled girl dances in bare feet. This causes the Fisherman to reflect on how the Mermaid has no feet and cannot dance, following which he feels “a great desire.” He decides to temporarily reunite with his Soul so that he can go and see the dancing girl.
The Fisherman and his Soul set out together, and after two days travelling they come to a city, where the Soul tells the Fisherman to take and hide a silver cup. On the evening of the third day they come to a city where the Soul tells the Fisherman to strike a child, and finally in the third city the Soul instructs the Fisherman to kill a merchant. Each time, the Fisherman does what the Soul tells him, and afterwards asks why the Soul instructed him to do an evil thing. Eventually, the Soul explains that because he was sent out into the world without a heart, he has learned to do and love evil things. The Fisherman now tries to send his Soul away again but finds that he’s unable to do so.
The next day, the Fisherman is determined to go back to the sea and confess his sins to the Mermaid. When they reach the shore, however, the Mermaid won’t respond to the Fisherman’s calls. Nonetheless, the Fisherman builds a house and for a year goes out every day calls to her. All the while, the Soul tries to tempt him with both evil and good deeds. After the second year, the Sea-folk bring the dead body of the Mermaid up onto the shore. The distraught Fisherman clings to her body, and at the moment his heart breaks the Soul manages to get back inside. The Fisherman drowns soon after.
The following morning the Priest comes to bless the sea but refuses to do so when he sees the bodies of the Mermaid and the Fisherman lying together. He remains adamant that their love is cursed and tells the people to bury them in an unmarked grave in the corner of the Field of the Fullers.
On a holy day three years later, the Priest enters the chapel and sees strange flowers covering the altar. Overcome by their curious beauty and smell, he finds he no longer wants to speak of the wrath of God, but “of the God whose name is Love.” After giving mass, he learns that the strange flowers have grown out of the Fisherman and the Mermaid’s grave. The next morning, he goes out and blesses all “the things in God’s world,” so that “the people were filled with joy and wonder.”
