At the end of the Second Age the King of the Mountains swore allegiance to Isildur at the Stone of Erech. But when war against the Dark Lord came the king proved faithless for he had worshipped Sauron in the Dark Years and still believed the dark to be greater than the light. And so Isildur said to him:
“Thou shalt be the last king. And if the west prove mightier than thy Black Master, this curse I lay upon thee and thy folk: to rest never until your oath is fulfilled. For this war will last through years uncounted, and you shall be summoned once again ere the end.”
The miserable story of the King of the Mountains acts as a kind of parable within The Lord of the Rings concerning the fate that awaits all who give way to the Dark believing either that their advantage lies that way, or that they have no choice, or some combination of the two. The story of Saruman is another expression of this reality and, if Sauron had triumphed, no doubt the story of the king and people of Harad and the other allies of Mordor would have been another. Isildur’s curse is not an act of arbitrary power. He simply declares what all worshippers of the Dark most truly desire; to exist in the darkness.
When Aragorn declares that he is the true king, the heir of Isildur, he calls the Dead to fulfil their oath. They must now serve him. Unlike the hapless Baldor, son of Brego the second king of Rohan, who sought to tread the Paths of the Dead in his own pride and without authority, Aragorn comes as one to whom authority has been given and so the dead must obey him. Baldor died because the way was shut “until the time comes”. The time has now come. The king has spoken and the dead must hear.
In one of his Advent reflections that you can find in his collection, entitled Waiting on the Word, Malcolm Guite calls Jesus “the king who walks alongside us disguised in rags, the true Strider.” https://malcolmguite.wordpress.com/2015/12/22/o-rex-gentium-a-sixth-advent-reflection/ This reference to Aragorn belongs to a poem inspired by the Advent antiphon, O Rex Gentium, O King of the Nations and their desire. The Lord of the Rings is an Advent work proclaiming light in the darkness as we saw a few months ago when we heard Frodo cry out “Aiya Eärendil Elenion Ancalima!”, Hail Eärendil O Brightest of Stars! when he was lost in the utter darkness of Shelob’s Lair. https://stephencwinter.com/2016/01/12/the-dayspring-from-on-high-comes-to-the-aid-of-the-hobbits/ Advent is also the time when we long for the true king to come and heal the lands. We long for “the true Strider”. The Lord of the Rings shows us those, like Faramir, who have kept the faith, waiting for the true king and perhaps for the restoration of Númenor and maybe even the deepest reality of all, that to which Númenor, even at its most true, could only point to. It also shows us those, like Denethor, who lose faith, or those like Saruman or the King of Harad who come to believe in a perversion of the Advent hope believing the lie that declares that it is the dark that is the true reality.
Aragorn’s journey through The Paths of the Dead calling the dead to obedience and so to an end to their misery also recalls the ancient story of how Jesus went down to the dead after his death on the cross and so harrowed hell leading the dead from despair to life.
This is the journey that Aragorn now takes with the companions who follow him and he points us to the true Strider who calls us, too, to follow him through darkness into light.