The Barrow Downs were once the sacred burial ground of men, but became haunted when tortured spirits fled across Middle Earth out of the Witch Kingdom of Angmar, trying to escape the unbearable light of the sun which would destroy them and turn them to mist. The Barrow Wights were these spirits whose bodies had been destroyed, and sought other bodies in which they could dwell. They manipulated the bones and jewelled armour of the ancient kings of men, and would enchant their victims, who would lose all will of their own. The victims would be taken into the treasure filled tombs under the downs and laid on a stone altar, bound with gold chains, draped in the cloth and jewellery of the ancient dead before being killed with a sacrificial sword.
Frodo, Sam, Merry and Pippin travelled through the Barrow Downs, and in the fog became trapped by the Wights. They were placed on a cold stone slab, and as Frodo came to himself he saw that they were dressed in white cloth, adorned with jewels and treasure, and that a sword lay across their necks. A cold song began, and changed to an incantation, part of the ritual in which the Wights planned to kill the hobbits. Frodo mustered his courage, grabbed a nearby sword and attacked the Wight's hand that reached towards the hilt of the sacrificial sword. He recalled the song of Tom Bombadil, and began to sing. Tom arrived and opened the Barrow, letting in light which destroyed the Wights and freed the Hobbits. He said words over them to lift the Wights' enchantments then from the Barrow provided each hobbit with a leaf shaped dagger, wrought with red and gold serpent shapes and set in black sheaths. These were knives long ago made by the men of Westernesse and stood the hobbits in good stead as they continued on their journey.