 In chapter 157 of Njáls saga , a man named Dörruð witnesses 12 people riding together to a stone hut on Good Friday in Caithness . The 12 go into the hut and Dörruð can no longer see them . Dörruð goes to the hut , and looks through a chink in the wall . He sees that there are women within , and that they have set up a particular loom ; the heads of men are the weights , the entrails of men are the warp and weft , a sword is the shuttle , and the reels are composed of arrows . The women sing a song called Darraðarljóð , which Dörruð memorizes . 
