Vainamoinen, held captive in the north, buys his freedom by promising that the smith Ilmarinen will forge a Sampo for the mistress of Pohjola, and that the smith will have her daughter in return. Ilmarinen is carried north and set to work. The runes list what goes into the furnace: the tip of a swan quill, the milk of a barren cow, a single grain of barley, the wool of a summer ewe. Three false things rise out of the fire first, a crossbow, a boat and a heifer, each beautiful and each with a vice in it, and each is broken up and thrown back. On the fourth attempt the Sampo comes out, with a mill on one side, a salt mill on another and a money mill on the third, and a lid of many colours.
It is then hidden. The mistress of Pohjola sets it inside a copper mountain behind nine locks, and it grows roots nine fathoms deep into the earth, because the thing that grinds without stopping is worth more than the daughter it was traded for.
The heroes come back for it. Vainamoinen puts the household to sleep with a kantele made from the jawbone of a great pike, the Sampo is dug out and carried to the boat, the pursuit is joined, the mistress of Pohjola takes the form of an enormous bird, and the Sampo is broken in the struggle. The pieces sink or wash ashore, and what came ashore is the reason the land bears anything at all.