Mabinogion: third branch
Manawydan and Rhiannon become close friends with Pryderi and his wife Cigfa. One day they take a walk to the throne of Arberth (Gorsedd Narberth) to look over the land where a mist of enchantment falls on them.
When the mist lifts, the kingdom of Dyfed is deserted - everyone and everything has disappeared without trace. They search for two years throughout Dyfed but find no humans or animals.
Manawydan suggests they earn a living making saddles in England. The saddles are so beautiful and well made that, before long, the other saddlers of Hereford plot to kill Pryderi and Manawydan and Pryderi.
Although Pryderi wants to stay and fight, Manawydan suggests they move elsewhere. They make shields, shoes and saddles, and but again are driven away by tradesmen as they travel from town to town. At Manawydan's suggestion they move back to Arberth.
One morning while out hunting with their hounds they come upon a shining white boar. The animal leads them to a huge castle which appears from nowhere in the forest.
The hounds follow the boar into the fort and Pryderi, ignoring Manawydan's warning, follows them. The fort is deserted inside and Pryderi sees a golden cauldron hanging over a well and, reaching out to take hold of it, becomes stuck to it.
Meanwhile, Manawydan returns to the court at Arberth. Disgusted with his disregard for her son, Rhiannon rushes to help Pryderi. She finds him unable to speak, and she too becomes stuck to the cauldron. At nightfall the fort disappears with them inside.
Manawydan leaves for England with Cigfa to work as a shoemaker. Again, his shoes are much in demand, and the shoemakers of the town plot to kill him. Driven away, Manawydan and Cigfa return to Dyfed.
Manawydan becomes a farmer and sows three fields of wheat. At harvest time he goes to reap the first, but it is stripped bare during the night. The following day he goes to reap the second field, but it too is stripped bare.
He keeps watch on the third field the next night and, at midnight, sees a horde of mice attacking the crops Manawydan manages to catch a fat, slow mouse which he decides to hang for eating his crops.
He goes to kill it on the throne of Arberth, where he meets a cleric and a priest who offer him money for the mouse's life. A bishop appears and pleads with Manawydan, but he won't free the mouse. When the bishop asks Manawydan to name his price, he asks for the spell on Dyfed to be lifted and for Rhiannon and Pryderi to be released.
The bishop is Llwyd, son of Cil Coed, a friend of Rhiannon's jilted lover Gwawl from the first branch of the Mabinogi. He put Dyfed under the spell to avenge the humiliation of Gwawl.
The mouse is revealed to be Llwyd's pregnant wife, and the rest of the mice are her ladies-in-waiting and his soldiers who were sent to destroy Manawydan's fields.
As a result of Manawydan's patience and resourcefulness, the spell is lifted and Dyfed is restored.