“The Ellylldan is a species of elf exactly corresponding to the English Will-o’-wisp, the Scandinavian Lyktgubhe, and the Breton Sand Yan y Tad. The Welsh word dan means fire; dan also means a lure; the compound word suggests a luring elf-fire.” – Wirt Sykes, British Goblins: Welsh Folk-lore, Fairy Mythology, Legends and Traditions p.19
“About the piskies Mr Rowe said this: ‘People would go out at night and lose their way and then declare that they had been pisky-led. I think they meant by this that they fell under some spiritual influence – that some spirit led them astray’… Mr Rowe’s sister added: ‘If we as children did anything wrong, the old folks would say to us, “The piskies will carry you away if you do that again.”‘” – W.Y. Evans-Wentz, The Fairy-Faith in Celtic Countries p.147-8
The story of Elidyr and the Golden Ball goes like this. In Wales there was once a boy called Elidyr. His tutor was cruel, and one day he ran away. At first he wandered hopelessly and hungrily, but then an Ellyllan, or local elf, took pity on him and led him away — underground, to a beautiful country full of forests and meadows. He was led to see the king of the country, the King of the Tylwyth Teg, who told Elidyr to wait on his son. The king’s son and Elidyr became friends, and would often play with a golden ball. But Elidyr missed his mother, and asked to be allowed to go and see her. On one of his visits, she asked him to bring her some fairy gold. “But I was told never to take anything out of that land,” Elidyr protested. His mother insisted. “What harm can it do?” she said. “The king has hundreds of golden balls – he won’t miss just one.” So on his next visit, Elidyr made sure no one was watching, and took the golden ball with him. At first he walked, but then he started to move faster and faster, as he heard tiny footsteps behind him. When he reached his mother’s house, he was running. He stumbled at the threshold, and the ball fell out of his hand. Two little men caught up with him, grabbed the ball, and ran away with it, calling Elidyr a thief and a traitor as they ran. Full of remorse, Elidyr went back to the river bank where he had gone underground into the land of the Tylwyth Teg, but he could find no opening into the ground. The land of the Tylwyth Teg was closed to him forever.1
When I was little, my grandfather would tell me stories about will o’ the wisps, and people who were lost in forests because the fairies led them astray. My grandfather told me a lot of fairy stories. They were land-focused, usually set in the woods behind his house — which were probably tiny, but to five-year-old me, seemed like a giant, mysterious forest. The kind of forest you could get very lost in, if the fairies wanted you to.
The Ignus Fatuus, or ‘foolish flame’, is a blue light that appears in marshes when plant-life is decaying there.2 Folk names for this phenomenon include will o’ the wisp, Ellylldan and Elf-Fire. The fire was said to be made by trickster elves of the forests, valleys and marshes (or, in Welsh, Ellyllan) — elves that could lead people astray, into the marshes, to be lost forever. Sykes describes how modern farming methods have cleared the old bogs,3 destroying the lights that led to the legends of people being led into the marshes by fairies and becoming lost there. But the stories carry on.
Even if inspired by bog fires, the tales of elf abduction range further than that. There are stories from all across Britain of people being led astray by goblin-like creatures. In Cornwall, to be led astray by spirits is to be ‘pisky-led’4.The piskies weren’t always tricksters, though. Some were said to have led people home with their lanterns, and they would come to some homes and help with farming and domestic work, like brownies in Scotland and northern England. That was less the case for the Welsh Ellyllan, who were the wild spirits of the forests and valleys, but even in Wales there were some stories of Ellyllan who helped their human neighbours — like the elves who helped Rowli Pugh, on the condition that his wife swept the hearth and left a candle out for them every night.5
I get lost all the time — I can get lost going from the library to my house, a two-minute journey. I tend to live in my own head, which makes for taking the wrong turn a lot of the time. I make offerings regularly to the local Good Neighbours. Like Elidyr of the Golden Ball, I fancy that the fair folk are kind to easily-lost village idiots like me. Just as long as we don’t steal any of their gold.
 W. Jenkyn Thomas, The Welsh Fairy Book, 1908.
 Mark Alexander, A Companion to the Folklore, Myths and Customs of Britain, 2002.
 Wirt Sykes, British Goblins: Welsh Folk-lore, Fairy Mythology, Legends and Traditions, 1880.
 A Companion to the Folklore, Myths and Customs of Britain.
 British Goblins: Welsh Folk-lore, Fairy Mythology, Legends and Traditions.
W.Y. Evans-Wentz, The Fairy-Faith in Celtic Countries, 1911.