The Spirit World, also known as the Underworld or the Other World, is a region that may be under the surface of the earth or in a hypothetical parallel universe. It may also be connected in some way to Avalon, the Land of Eternal Youth where the Sidhe dwell, served by the pixies. The Spirit World is apparently the place where the souls of the recently departed go and is possibly the place where heaven and hell are located. It is a place of darkness and of ancient and evil spirits.
The Spirit world is separated from the world of the living by the Veil, located at Gateways between the worlds. The Pool of Nemhain is the last of the five Gateways that separate the world of the living from the world of the dead (Lancelot du Lac). The Cailleach is the gatekeeper to the Spirit world and guardian of the Veil (The Darkest Hour). She may inhabit the Spirit World as well.
Some spirits that were badly wronged cannot find peace in the Spirit world. They try to find their proper place in the Underworld, but the unjust nature of their death has denied them that. Because of this, the druids built shrines to bind them to a particular location on the earth (A Herald of the New Age).
The Horn of Cathbhadh, a magical tool which had the power to summon the spirits of the dead, was used, long before the time of the Great Purge, each year at Beltane by the High Priestesses who would gather at the Great Stones of Nemeton to summon the spirits of their ancestors. In the days of the Old Religion, however, the priestesses trained for years before entering the Spirit world, since it was fraught with dangers. The one thing they were schooled never to do was to look back at the spirit, as the Veil closed. If they had done it, they would have released the spirit into this world.
Arthur Pendragon blew the Horn to talk to his father, entering an undefined region of unnatural bright light, but since he had looked back at him before returning to the world of the living, he had to use the magical tool again to reopen the Veil and force Uther into the Spirit world (The Death Song of Uther Pendragon).
Inhabitants of the Spirit WorldEdit
The main creatures that dwell in the Spirit World are the Dorocha, the numberless voices of the dead.The manticore is a creature that lives in the Spirit world and cannot prolong its existence in the world of the living. Its life source is, in fact, the ancient evil that exists in the Spirit world. To come into this world, the manticore has to use a portal (Love in the Time of Dragons). Another creature that dwells in the depths of the Underworld is the Fomorroh, which can be conjured into this world but has to be kept in the dark, for it is not used to being out in the light (A Servant of Two Masters). Apart from these evil beings, the Spirit world seems to be populated by good creatures as well. The Vilia are the benevolent spirits of the brooks and streams that were released when the Veil was torn.
And of course, the Spirit is populated by the Spirits of the dead. The "afterlife" is located either in this realm or just beyond it, where even the likes of Uther Pendragon are able to find peace. Spirits can take any form they choose and can only become more powerful in death, especially those who already have Magic.
- In a deleted scene from The Secret Sharer, Morgana, having been badly injured by Merlin's whirlwind spell in the previous episode and lying on the brink of death, is about to enter the Spirit world. There she sees her sister Morgause, still with injuries on the right side of her face and surrounded by the spirits of the dead (people dressed in grey and with their hands extended to her). Morgause gives Morgana a magical coin, "the price of a soul" (as the Witch describes it to the Dochraid in Lancelot du Lac) that is able to revive the High Priestess and let her leave the Spirit world, healed. Morgana will use the coin, throwing it into the dark waters of the Pool of Nemhain, to summon Lancelot's shade (Lancelot du Lac).
- It is possible that the Spirit World is based off of Tartarus from Greek Mythology as it is presumed to be the resting place of evil people and ancient darkness.